PRACTICAL ARITHMETIC €t)e Cuskegee Knstitutc Series of Cms EDITED BY J. R. E. LEE DIRECTOR ACADEMIC DEPARTMENT TUSKEGEE NORMAL AND INDUSTRIAL INSTITUTE Introductory Note In presenting this volume the author endeavors to set forth matter which will give training and drill in all of the fundamental processes in arithmetic. The matter con¬ tained herein has all been taken by Mr. D. W. Woodard, the author, from the industrial and business operations of the Institute. He has visited every department of the Institution, has examined all the books, and has had nu¬ merous conferences with every instructor. He has not found a single practical, workable operation in arithmetic that has not been exemplified in some of the work connect¬ ed with the Institution. The problems are therefore local in their setting. The Accounting Department, the Mechanical Department with its various construction operations, and the Agricultural Department through its planting, harvesting and productive endeavors, together with the various industries for the training of young women, have all furnished the material for the operations in this volume. Th is book in the present form is the Tuskegee Institute Edition. It comprises one of the series of what is known as "The Tuskegee Institute Series of Texts." This series of texts covers various branches taught in the usual secondary course. In this text and others that are under way, claim is laid to concrete and practical application of all the operations and principles set forth therein. J. R. E. Lee, Editor. II PRACTICAL ARITHMETIC TUSKEGEE INSTITUTE EDITION PRACTICAL ARITHMETIC TUSK EG EE INSTITUTE EDITION By DUDLEY W. WOODARD HEAD OF DIVISION OF MATHEMATICS TUSKEGEE NORMAL AND INDUSTRIAL INSTITUTE TUSKEGEE INSTITUTE, ALA. 19 11 Jnstitute ©regis T'uskegee Institute, Alabama 1911 PREFACE This book has been prepared in response to a long felt need of the students of the Tuskegee Normal and Indus¬ trial Institute. At this institution, the attempt is made to connect the arithmetic in a vital manner with the every¬ day interests and exercises of the students. The subject i9 presented as a necessary tool for doing certain things, for solving specific problems. Under this conception of the function of arithmetic, the course centers about the problems. If this book has any distinctive feature, it lies in the character of the prob¬ lems. Attention is called to the very large number of problems in which the data must be gathered at first hand by teacher and student. In fact, it is impossible to carry out the purposes of this book within the narrow con¬ fines of the class room. In the gathering of problems for this work I have had the hearty co-operation of the members of every depart¬ ment of the Institute and wish to express here my grate¬ ful appreciation of the ;ame. D. W. WOODARD. Ill PRACTICAL ARITHMETIC FUNDAMENTAL OPERATIONS NUMBERS. UNITS In making bread at the Institute Bakery, flour, yeast, sugar, lard, salt, and water are mixed together. These materials are mixed according to a recipe, which tells how much of each kind of material must be used. Thus, the recipe used by the bakers in making bread on a certain day required 700 pounds of flour, 1 pound of yeast, 20 pounds of sugar, 10 pounds of lard, 5 pounds of salt, and 40 gallons of water. In the statement just made, 700, 1, 20, 10, 5, and 40 are called numbers. The symbols or characters, 7, 0, 1, 2, 5, 4, used in writing these numbers are called figures or digits. As you have already learned, the figures used in writing numbers are: 123456 7 8 90 one two three four five six seven eight nine zero Numbers like 40 and 5 are often called abstract or un¬ named numbers. On the other hand, the expressions, "40 gallons" and "5 pounds" are called concrete or named numbers. 1 F U N D A M ENTAL OPERATIONS Other numbers are: 9 dollars, which tells how much each student of the Institute pays a month for board; 39 miles, which tells how far Chehaw is from Montgomery by railroad; 7 days, which tells how many days are in a week; 25 cents, which tells the price per pound of a cer¬ tain grade of coffee sold at the Institute Commissary. Now, one of each of the things named in the above number expressions is called a unit. Thus, 1 pound, 1 gallon, 1 dollar, 1 mile, 1 day and 1 cent are units. Exercise 1 1. Find out what units are used at the Institute Dairy Barn in stating the amount of milk given by a cow in a day. 2. What units are used at the Creamery in selling this milk to customers? 3. Name the units used in the Dressmaking Division in measuring cloth. 4. Point out on the yard stick, pocket rule, or tape measure some unit lengths. 5. What units are used at the Paint Shop? 6. What units are used at the Poultry Yard in stating how many eggs are bought, etc.? 7. Name some units used in the Cooking Division in connection with recipes. 8. Find out what units are used at the Canning Factory. 9. Name some units used at the Commissary. 10. Name some of the units used on the Farm, Truck Garden, and Orchard. 11 Name any other unit not already mentioned. READING AND WRITING NUMBERS 9 READING AND WRITING NUMBERS Exercise 2 Read carefully the statements given below. 1. In 1910, 91,972,266 persons were counted as living in the United States of America. The number, 91,972,266, is read "ninety-one million, nine hun¬ dred seventy-two thousand, two hundred sixty-Mx.1' The names of the orders or places occupied by each figure in the number are as follows: c re c o c .2 *5 a -S h X z h 9 1 9 7 2 2 6 6 2. A student working in the Brickmasonry Division in one month earned $3.84. The amount of money earned by the student is read "three dollars and eighty-four cents." The period, called the decimal point, is used to separate the number of dollars from the number of cents. In the amount given, 3 states the number of dollars, 8, the number of dimes, and 4, the number of cents. Observe that in reading numbers, the word "and" is used only to separate that part of the name of the number coming before the decimal point from that part following the decimal point. 3. In February, 1910, the students in the Mattress- making Division earned $52.45; in the Plain Sewing Division, $27.50; in the Dressmaking Division, $47.05; in the Ladies' Tailoring Division, $43.08; in the Millinery Division, $42.70. 4. During the month of December, 1910, the students of the Institute paid in cash on their board bills $3,443.98. Of this amount, the boys paid $1,778.10, and the girls. 10 FUNDAMENTAL OPERA I IONS $1,665.88. (Give the amount of money expressed by each figure in each of the three numbers just given.) 5. During one year the Creamery handled 71,743 gal¬ lons of milk. For this time, 15.757 gallons of whole milk and 31,851 gallons of separated milk were used by the Hoarding Department. 6. The following is taken from the report of the Prin¬ cipal to the Trustees of the Institute for the school year 1909-1910: "In the regular Academic and Industrial Departments of the School, we have had during the past year an attend¬ ance of 1,662 students, 561 girls and 1,101 boys, from 35 states and 21 foreign countries. Besides the enrollment in the main departments of the institution, there has been an average attendance of 153 at the Children's House or Training School; 98 in the Town Night School and 27 in the afternoon cooking classes in the Town of Tuskegee; 10 in the night Bible classes taught in Phelps Hall, and 227 upon the Two Weeks' Short Course for farmers held in January. Thus, we have been responsible for reaching and teaching, all told, for greater or less time, 2177 per¬ sons. '' (In numbers, 1662, 1101, and 2177, tell how many of the students is expressed by each figure. Exercise 3 Write in figures the numbers occurring below, using the dollar sign and decimal point in the case of money. 1. In March, 1911, there were printed at the Institute Printing Office fifteen thousand copies of The Southern Letter, nineteen thousand, two hundred copies of The Tuskegee Student, twelve hundred fifty copies of the READING AND WRITING NUMBERS 11 Jo urnal of the National Medical Association, and one thousand copies of the National School News. 2. In one year, eleven thousand, six hundred bushels of sweet potatoes were grown on the Institute Farm. 3. The girls working in the Laundry earned six hun¬ dred forty-four dollars and seventeen cents in December, nineteen hundred and ten. 4. On May thirty, nineteen hundred ten, the endow¬ ment fund of the Institute amounted to one million, four hundred one thousand, four hundred forty dollars and seventy-seven cents. 5. Find out what is meant by the "endowment fund." 6. According to the thirteenth census of the United States, the population of the state of Alabama was given as two million, one hundred thirty-eight thousand, ninety three. 7. Find out what is meant by "the census." When was the thirteenth census taken? When will the next census be taken? ROMAN NUMERALS A system of writing numbers, called the Roman system, employs letters instead of the figures ordinarily used for this purpose. The letters, with their values, are: I V X L C D M 1 5 10" 50 100 500 1000 The following will show how numbers are written in this system: 12 FUNDAMENTAL OPERATIONS II =2 XX 20 XCIX = 99 III =3 XXII 22 CLXI = 161 IV (IIII) = 4 XXXV 35 MDCXI = 1611 VII = 7 XLVII 47 LXXIX = 79 VIII =8 LXXXVII = 87 CCCXVIII = 318 IX =9 MCMX1V = 1914 DXIII = 513 Exercise 4 IVrite in the usual (Arabic) figures. MCMXXXIV LXXVII DCXCIII XLVI CCCXVIII MVIII Express in Roman numerals. 76 54 85 39 111 93 48 1016 1724 1913 679 364 Bring into class three instances in which you have ob¬ served the use of Roman numerals. ADDITION Exercise 5 Give results quickly. 2 + 3 2 + 5 2 + 4 2 + 7 2 + 6 2 + 8 3 + 3 3+4 3 + 6 3+5 3 + 7 4 + 5 4 + 6 5 + 6 2 + 9 3 + 9 4 + 7 6+6 7 + 6 8 + 3 8 + 5 9 + 4 6 + 9 5 + 7 8+6 9 + 7 9+8 9 + 9 10+3 10 + 8 11+2 11+5 ADDITION 13 12 + 7 15 + 5 1 + 3 + 2 7 + 4 + 5 10 + 9 13 + 6 6+7 + 5 9+7 + 7 12+ 4 + 3 Add quickly 11 + 9 13 + 8 1 + 4 + 5 8 + 5 + 4 12 + 3 15+4 5 + 8+7 8+5 + 9 10 + 7 + 3 the following 12 + 9 17+5 5 + 3 + 5 7 + 6+6 13 + 4 16+3 9 + 9 + 2 2 + 9 +8 12 i 6+ 4 )l twins: 10+10 18+ 4 5 + 6+ 4 3 + 7+ 9 14+ 5 17+ 3 8 + 4+ 7 6 17+ 9 3 + 14^ 5 3 Omit unnecessary words in adding. For instance, in adding 5 this column, beginning at the bottom say: 6 7, 8, 10, 16, 21, 24. 2 1 In this example, the numbers, 3, 5, 6, etc., to be added, 7 are called addends, while the result, 24, is called the sum. ~2A~ If columns are added from the bottom upward, check re¬ sults by adding from the top downward. 4 5 7 8 3 3 2 4 2 4 8 2 3 6 1 6 6^ 1 3 5 8 9 6 7 7 6 8 9 6 5 5 6 8 4 4 8 5 7 6 7 4 3 1 2 3 4 8 6 9 1 2 5 14 FUNDAMENTAL OPERATIONS 1 2 7 5 6 4 9 7 7 9 8 3 8 3 1 6 3 1 7 9 5 7 6 9 8 7 8 7 9 5 3 4 2 6 5 3 Exercise 6 1. During the month of March, 1911, the Creamery received from the Institute Dairy Barn 6574 gallons of milk and purchased from neighboring farmers 1674 gallons of milk. How many gallons of milk were handled at the Creamery during this month? 6574 gal. Adding: 4+4 = 8; put down 8; 7 tens + 7 tens = 1674 gal. 14 tens; 14tens=l hundred+4 tens; put down 4 in 8248 gal. tens' place of results; 6 hundreds-|-5 hundreds-f- 1 hundred = 12 hundreds; 12 hundreds-|-l thousand = 2 hundreds; put down 2 in hundreds' place of the result; 1 thousand+6 thou- ands +1 thousand = 8 thousands; put down 8 in the thousands' pla'^ of the result. Then, the total number of gallons of milk handled at the Cream¬ ery during March, 1911, was 8248. 2. During the period mentioned in the preceding problem, the sales of the Creamery on the retail wagon routes were as follows: Route No. 1, $234.64; Route No. 2, $157.30. Find the value of the dairy products sold on these two routes for the month. $234.64 Adding, the value of the sales on the two 157.30 routes for the month is found to be $391.94. $391.94 In adding United States money, the addends are to be so placed as to bring decimal point beneath decimal point, thus having the figures of the same order in the same column. ADDITION 15 3. On one day the hogs of the Swine Raising Division were kept in ten groups on the farm. The record of the division for the day gave the number of hogs in each group as follows: Group 1 130 hogs Group 6 130 hogs 2 17 7 50 3 94 8 148 4 80 9 110 5 130 10 104 Find the number of ho;js in the entire herd. 4. On March 12, 1911, the menus given below were served the students boarding in Tompkins Hall. The cost of each item is given. Breakfast: rice, $4.80; butter, $12.60; syrup, $7.60; coffee,$7.98; rolls, $14.12. Dinner: sausage, $20.00; rutabagas, $10.50; corn, $6.78; bread, $13.80; milk, $6.40; pie, $20.25. Supper: ginger bread, $12.57; light bread, $12.00; syrup, $7.60; tea, $5.00. Find the cost of the food for each meal and for rhe day. 5. Find out (through teacher) the cost of the various food-stuffs used for the meals of students in Tompkins Hall for some recent day, and compute the cost of the same for the day. 6. In July, 1910, the cost of operating the Boarding Department was as follows: provisions, $4,095.03; labor, $885.16; other expenses, $478.68. Find the total cost of operating the department for the month. 7. The cost of working the cabbage crop on the In¬ stitute Farm during April, 1910, was as follows: labor of hired men, $11.93: labor of students, $58.79; team hire, $16.80; fertilizer, $19.50. What was the cost of working the crop for the month? 8. In 1910 the following was paid for student labor in working the sweet potato crop of that year: Jan. and 16 FUNDAMENTAL OPERATIONS Feb., $61.96; Mar., $53.45; Apr., $66.67; May, $108 34; June, $368.30; July, $494.90; Aug. $201.99; Sept., $94.35; Oct., $106.50; Nov., $224.00; Dec., $29.55. Find the amount paid students for working this crop. 9. The value of the seed used by the Agricultural De¬ partment during March, 1910, was as follows; corn, $23.10; rape and rutabagas, $22.00; carrots and mangels, $31.45; beets, $70.00; cantaloupes, $15.00; watermelons, $4.38; turnips, $6.80. Find the total cost of these seeds. 10. For one month the students pursuing mechanical trades in the Institute earned in the various divisions the amounts given below: Blacksmithing . $151.81 Brick masonry $303.46 Carpentry . 339.22 Plumbing 168.74 Machinery . 473.53 Harnessmaking . 86.35 Printing . 113.25 Painting . 77.34 Sawmilling 50.95 Wh eel wrigh ting 84.43 Repair . 113.84 Tailoring 138.39 Tinsmithing . 88.90 Shoemaking . 101.66 Electricity . 120.01 Brickmaking 22.67 Foundry 33.04 Find the total earnings of the students in the mechanical divisions for the month. 11. Most of the employees of the Institute who trade with its various departments use for this purpose coupon books. The value of the trade carried on with the different divisions of the Institute by means of these coupon books during November, 1910, is given below: Sales Room . . $154.27 Commissary . . $964.29 Dairy .... 142.25 Truck Garden . 30.01 Printing . . . 4.52 Dressmaking . 5.60 Carpentry . . 13.08 Goat Herd . . 4.50 Sawmilling . . 4.50 Fuel Account . 25.10 ADDITION 17 Hospital 44.90 Repair 2.60 Shoemaking . 16.95 Horse Barn . 40.97 Painting .61 Poultry Raising . 4.05 Millinery . 6.00 Blacksmithing . .80 Mattressmaking 3.85 Tinsmithing 10.61 Brickmaking . .80 Plain Sewing .25 Practice Kitchen 9.30 Farm .... 12.60 Brickmasonrv .54 What was the value of the trade in coupons for the month? 12. The daily receipts for the Institute Commissary for the month of February, 1911. were as follows: February Cash Coupons 1 $17.14 . . $ 18.37 2 15.82 . . 105.15 3 11.55 . . 59.21 4 ... 14.53 . . 80.33 5 42.30 . . 72.11 7 . . . 16.27 . . 38.90 8 : 15.36 . 27.20 10 24.40 . . 45.77 11 16.48 . . 31 84 13 38.43 . . 52.71 14 39.87 . . 32.50 15 ... 17.26 . . 47.20 16 16.13 . . 27.79 17 7.95 . . 17 68 18 22.25 . . 56 87 20 36.80 . 49.63 21 15.05 . . 28.55 22 13.04 . . 20.77 23 11.11 . . 15.25 24 16.26 . . 16.47 25 ... 16 57 . . 19.37 27 41.42 . . 86.73 28 14.95 . . 37.95 Find the total value of the sales for the month. IS FUNDAMENTAL OPERATIONS SUBTRACTION Exercise 7 1. A student, having $8, paid $2 for a uniform hat. How much did she have left? To find out how much the student had left, we must take (sub¬ tract) $2 from $8. Now, $8—$2 = $6. Then, the student had $6 left, $'8 from which we take $2, is called the minuend; $2, which is subtracted is called the subtrahend; $6, the result, is called the remainder or difference. 2. The lace used in trimming a dress was bought in a bolt containing 17 yards. When the dress was finished, 8 yards of lace remained unused. How many yards of lace were used in trimming the dress? 3. In measuring a student for a skirt in the Dress¬ making Division, the skirt measure from the waist to the floor was found to be 42 inches. The girl wished her skirt to be 4 inches from the floor. How long should the cloth for this skirt be cut, allowing 3 inches for a hem? 4. The skirt measure of another student from the waist to the floor was found to be 39 inches. This stu¬ dent desired her skirt to be 5 inches from the floor. How long should the cloth be cut, allowing 4 inches for a hem? 5. A student measured 43 inches from the waist to the floor. How long should the cloth for a skirt for this student be cut, allowing 4 inches for a hem and 3 inch¬ es for each of two tucks, and making the skirt when finished 5 inches from the floor? 6. Find out the method used in the Institute Com¬ missary in making change. For instance, if your pur- SUB FRACTION 19 chases amount to ,$1.68 and you give the clerk a $2 bill, how does he count out to you the proper change? 7. Show how the change might be counted out to a purchaser who bought $3.76 worth of goods and gave the clerk $5 8. When the purchases amount to $13.33 and the pur¬ chaser gives the clerk three $5 bills, show how the change might be counted into the hands of the purchaser. Exercise 8 Supply the missing numbers. 3 + = 5 2 + = 6 4 = 7 5 H- = 8 4 + = 9 5 r =9 2 + -11 3 + = 10 6 i =12 5 + = 12 4 = 13 6 =14 7 + = 15 8 i = 17 9 i =19 7 + = 19 8 + = 20 5 =18 13 + = 16 12 = 19 14 =21 23 + = 30 37 + = 46 56 : =70 Give results rapidly. 9-3 12- 9 13- 4 14- 6 8-5 13- 7 16- 6 15- 9 10-6 17- 7 16- 8 19-10 11-5 18- 8 15- 10 17- 6 12-7 18- 9 19- 8 18-10 14-9 15- 8 23- 7 37- 5 50-8 67- 8 59- 4 71- 7 35-9 88- 9 43- 7 101-98 7 + 8- -5 9 5-7 3 5- ■6 10+ 2-7 3 + 9- -8 5 + 7-5 16 h 8- ■7 23+ 7-9 17 + 6 -8 4 + 18-7 51 + 6- -8 26+ 7-2 19-8 + 7 24- 7 + 9 53- 8 7 16- 9 + 6 20 F U N D A VIE N T A L O P E R A TIO N S Exercise 9 1. During the school year 1908-1909, there were en¬ rolled in the Institute 1494 students. In 1909-1910, 1662 students were enrolled. How many more students were enrolled in 1909-1910 than in 1908 1909? To find how many more students were enrolled in 1909- 1910 than in 1908-1909, we subtract (take) 1494 from 1662 as indicated below. 1662 4 units cannot he taken from two units. Take 1 ten 1494 (10 units) and add to the 2 units, making 12 units. 12 108 units—4 units 8 units. Since 1 ten was taken from the 6 tens, 5 tens are left. 9 tens cannot be taken from 5 tens. Take 1 hundred (10 tens) from the 6 hundreds and add to the 5 tens, making 15 tens. 15 tens—9 tens 6 tens. Since 1 hundred was taken from the 6 hundreds, 5 hundreds are left. 5 hundreds —4 hundreds 1 hundred. 1 thousand—1 thousand--0. Then, 1662—1494" 168. Therefore, there were 168 more students enrolled in 1909-1910 than in 1908-1909. Another method of subtracting 1494 from 1662 is that called the method of making change. ( See Exercise 7.) 1662 We are now looking for the number which when add- 1494 ed to 1494 will produce 1662. It is evident that the 168 figure in units' place of the number sought must be such that when added to 4, the figure 2 will be in units' place of the sum. According to this method, we proceed as follows: 4 ;-8=12, put down 8 1 - 9 <3 —16, put down 6 111 6, put down 1 1 O 1. 2. The Institute received a bill for a car of coal ship¬ ped from Bessemer, Alabama, in which the weights were specified as follows: SUBTRACTION 21 Gross 113,500 pounds Tare 34,500 pounds Net 79,000 pounds Find out what is meant in this connection by the words gross, tare, net. See actual coal bill furnished by teacher. 3. Find the number of pounds of coal received by the Institute in the three cars mentioned below. Gross Tare Car No. 1. 115,600 36,700 Car No. 2. 123,400 39,600 Car No. 3. 109,000 35,200 4. The population of thirteen Southern States for 1900 and 1910 is given below. Which state gained the greatest number of persons during the ten years? What was the total increase in population for all of these states together? 1900 1910 Alabama 1,828,697 2,138,093 Arkansas 1,311.564 1,574,449 Florida 528,542 752,619 Georgia 2,216,331 2,609,121 Kentucky 2,147,174 2.289,905 Louisiana 1,381,625 1,656,388 M ississippi 1,551,270 1,797,114 North Carolina 1,893 810 2,206,287 Oklahoma 790,391 1,657,155 South Carolina 1,340,316 1,515,400 T ennessee 2,020,616 2,]84,789 Texas 3,048,710 3,896,542 Virginia 1,854,184 2,061,612 5. On the following page is a reproduction of the monthly statement given each student of the 1 nstitute. The statement here reproduced is one that was given a student for the month ending January 31, 1911. Henry Davis IN ACCOUNT WITH THE TUSKEOEE NORMAL AND INDUSTRIAL INSTITUTE Statement for the Month Ending January 31, 1911 Debits ( IVhat the Student ogives the School ) Credits (What the School ou.es the Student To Balance last Statement Board and lodging for the month. Medicine and Hospital.. Shoemaking Tailoring .. .Sales Room Dressmaking Sewing... Millinery Cash Drawn Breakage and Fines Indebtedness to School By Balance last Statement Cash paid .. Work in Boarding Dept in Teachers' Home in Office. Choir. _ _ .. ... in Division: — Blacksmithing ... Carpentry... Dressmaking Klectncal .. Farm .. Latin deri ng Masonry.. Machinery... Printing Painting Sboemaking Tailoring 22 :i2 19 :i2 Balance due the Student This bill is due when received; payment must not be deferred later than the 15th. SUBTRACTION 23 What does "To Balance last Statement" mea1? What does "By Balance last Statement'' mean? Verify the above statement, that is, see if the student teally owes the Institute the amount indicated opposite "Indebtedness to School." In subtracting United States money put down numbers so as to bring decimal point beneath decimal point. M hyf 6. Another student for one month owed the Institute for board and lodging $8.50. The Institute owed him at the beginning of the month $7.86. This student earned by work on the farm during the month $10.26. Make out a statement showing the standing of the student. 7. A student for one month owed the Institute for board and lodging $6 80, for medicine and hospital charges, $5.85, for cash drawn, $.50. On the other hand, the In¬ stitute owed the student at the beginning of the month $1.82. The student earned by work on the farm $3 20, and by work for the Machinery Division, $1.00. How did the account of this student stand at the end of the month? 8. The statement of a student for one month showed that at the beginning of the month, the student owed the Institute $2.15. For board and lodging for the month, she owed $8.50. She earned by work in the Boarding Department, $2.75, by work in the Dressmaking Division, $1.78, by singing in the Institute Choir, $ 90. What was the standing of this student at the close of the month mentioned? 9. Verify your statement for last month. 10. For the year ending May 31, 1910, the receipts of the Institute lor current expenses and equipment were $319,964.31. Of this amount, $118,062.37 came in the FU\DAMENTAL OPERATIC)NS form of donations from individuals and organizations. How much was received from other sources than those just mentioned? 11. In the report of the Principal of the Institute for the year mentioned in the preceding problem, we find the following statement: "1 he value of our plant, including equipment and live stock, is now $1,279,248-/3, making an addition of $163 613.94 for the year for permanent physical plant." Find the value of the plant on May 31, 1909. 12. A hat made in the Millinery Division cost as fol¬ lows: shape, $.35; lining, $.06; straw, $1.25; quills, $1.25; thread, $.03; labor, $.50. This hat sold for $4.25. Find the gain. 13. Four students of the Cooking Division were given $1.00 and told to prepare a luncheon for six persons. The material used by the students in preparing the luncheon was as follows: flour, $.07; tomatoes, $.08; peas, $.15; salmon, $.15: eggs, $.05; lemons, $.03; lard, $.05; coffee, $.03; sugar, $.05; butter, $.05; crackers, $.05; milk, $.07; potatoes, $.03; baking powder, salt, and pepper, $.02. H ow much of the $1.00 given the students w7as left? 14. On another day, five students of the Cooking Division were given $1.50 with which to prepare a dinner for six persons. For this purpose they used the following: green peas, $.10; crackers, $.05; rice, $.05; beef, $.05; vinegar, $.05; chicken, $.30; butter, $.14; lettuce, $ 05; bread, $.10, coffee, $.05; sugar, $.15; eggs, $.05; milk, $.05; flour, $.10; gelatine, $.15. How much of the $1.50 given the students was left? 15. On January 1, 1910, the Institute oat crop then on hand was valued at $5542.00 During the year 1910, SUBTRACTION 25 $1993.21 was spent on the crop. The oats and hay rais¬ ed from the crop were valued at $8630.74. What was gained on this crop for the year? 16. The cost of raising the sweet potato crop of 1910 was $3588.10. T he value of the sweet potatoes raised was $8291.62. By how much did the value of the crop exceed the cost of raising it? 17. The growing of the corn crop of the same year cost $5433.42. The crop was estimated to be worth $5675.20. Find gain. MULTIPLICATION Exercise 10 1. How much does a student pay for board and lodg¬ ing who enters the Institute on September first and stavs until the close of the school year? 2. A student working in the House and Sign Paint¬ ing Division received 3 Cents per hour. How much did he earn in one full working day? 3. In some repair work done in the Harnessmaking and Carriage Trimming Division, 7 yards of buckram costing 12 cents a yard were used. Find the cost of this material. Give results rapidly. 5/6 Here we are required to multiply 6 by 5, that is, to take 6 five times. 6, the number multiplied, is called the multiplicand; 5, the number by which we multipy, is called the multiplier; 30, the result, is called the product. 3x6 5x4 6x2 9x11 2x7 4x3 5x6 10x11 4X6 6x3 7x4 llv 8 4x9 3x8 9x3 12x 7 8x4 6x7 7x7 lOx 9 5x7 7x8 6x6 12x 6 FUN DA VI EN PAL OPERATIONS 4x4 3x10 7x9 12 X 8 9x5 5x11 8x8 12 X 5 3x4 2 < v Perform multiplication first, then addition ) 6x7 ; 3 2x9 + 5 6x8 + 8 2X 7-9 5x7 + 8 3x8 + 5 7x7 + 7 6+ 9x7 8x9 + 3 8x7-6 5x6 + 4 9x 9—7 4x7-9 11x7-6 12x6-4 8x12-6 3x3x3 6x2x5 5x2x9 3x 4x6 2x3x8 2x4x8 1x9/9 3x 3x6 Exercise 11 1. The Bakery used on one day 4 barrels of flour. What was the weight of this flour, allowing 196 pounds to the barrel. 196 ft> If 1 barrel of flour weighs 196 pounds, 4 barrels will 4 weigh 4 times 196 pounds. 784 ft) The explanation of the multiplication of 196 by 4 is as follows: 4X6 units---24 units. Put down 4 and keep the 2 tens to add to the next product. 4X9 tens-—36 tens. 36 tens 2 tens ~ 38 tens. Put down 8 and keep the 3 hundreds to add to the next prod¬ uct. 4Xlhundred = 4 hundreds. 4 hundreds + 3 hundreds = 7 hun¬ dreds. Then, 4X196 = 784. Therefore, the 4 barrels of flour weighed 784 pounds. 2 The Institute bought at one time for the Foundry 7 tons of Number 2 pig iron at $14.50 per ton. The freight charge on this shipment was at the rate of $2.35 per ton. Find the total cost of pig iron. $14.50, price per ton of pig iron. $16.85 2.35, freightcharge per ton. / $16.85, total cost per ton of pig iron. $117.95,total cost of 7 tons. Note the position of the decimal point in the product ob¬ tained when $16.85 is multiplied by 7. MULTIPLICATION 27 3. During October, 1910, a student in the Dressmak¬ ing Division made 8 uniform skirts. The price paid for making one skirt at that time was $.15. Find the amount paid the student for this work. 4. A student in the Brickmasonry Division worked 9 full working days in one month at $.35 per day. What were his earnings for the month in this division? 5. If you put in full time at your work next month at full pay, what will be your probable earnings for the month? Show how you arrive at your estimate. 6. A family in Greenwood trading with the Institute Creamery bought during one week the following: 7 quarts of skimmed milk at $.02 per quart; 8 pints of whole milk at $.04 per pint; 3 pounds of butter at $.28 per pound. Find the amount spent by the family during the week for dairy products. Multiply as indicated 5x $649.08 6x $101.67 7X $8765.43 8x $5307.07 4X $3057.96 3 x $90706.59 10X5 10 X 10 10x$.05 10x$.08 10X$1.50 100x6 J 00x3 100x8 We see from the above that when an integer (whole number) is to be multiplied by 10, 100, 1000, etc., the 7 x 234 6x5478 6x 857 8x1854 4X9754 3 x 7528 5x6507 4X9995 8x8734 9X6006 7X4008 5x5307 Exercise 1. Give the products. 10x6 10X3 10x8 10x4 28 FUNDAMEN TAL OPERATIONS product can be found by annexing as many zeros to the multiplicand as there are zeros in the multiplier. When United States money is to be multiplied by 10, 100, 1000, etc., the product can be found by moving the decimal point in the multiplicand as many places to the right as there are zeros in the multiplier. Thus, 100x17 = 1700; 100x$3.25 = $325.00. 2. Announce immediately the products. 10x375 100 x 13 10 x $1.50 100x 55 1000x 97 100X $2.37 100x863 100x300 10 x $10.07 3. During the year 1910, the Blacksmith Shop used 80 tons of coal. This coal cost the Institute $2.35 per ton at the mines. The freight charge on the coal was $1.61 per ton. Find the total cost of the coal used by the shop for the year. $2.35, cost per ton of coal at mines. $1.61, freight charge per ton. $3.96, total cost of 1 ton of coal. $3.96 If the total cost of 1 ton of coal was $3.96, then 80 the total cost of 80 tons was 80 times $8.96, which $316.80 is *316-80- Now, 80 = 8X10. Then the product, 80 X $3.96, can he found by first multiplying by 8 and then by 10. Thus8X$3.96 = $31.68; 10X $31.68 =$316.80. But the actual work necessary to be done is indicated. 4. In December, 1910, a student in the Dressmaking Division made 40 pairs of the cuffs worn by the girls on their uniform dresses. For this work she received $.02 per pair. H ow much did the girl receive for this work? MULTIPLICATION 29 5. In the same month, the Dressmaking Division sold to students 20 uniform dresses at $2.00 each and 10 sets of white cuffs and collars at $.25 per set. Find the amount received by the division for these articles. 6. In making a set of harness for the dump carts used on the Institute grounds, 10 pounds of "Union" harness leather are used. This leather cost $.35 per pound. Find value of leather used in one set of this kind of harness. 7. The Institute bought for the Commissary from the Calumet Tea and Coffee Company of Chicago 20 five- pound cans of cocoa at $.28 per pound, and 100 one- pound cans of cocoa at $.29 per pound. Find the value of this order. 8. The Buell Manufacturing Company of St. Joseph, Mo., sold the Institute 60 blankets at $1.75 each. What was the amount paid for these blankets? 9. During the school year 1908-1909, families living in Greenwood bought of the Institute 132 tons of do¬ mestic coal at $6.50 per ton. Find the amount paid the Institute for this coal. To find the amount paid the Institute for the coal, we multiply $6.50 by 132. Why? (a) (b) $6.50 $6.50 132 132 13.00= 2 x $6.50 1300 195.00= 30 x $6.50 1950 650.00 = 100 x $6.50 650 $858.00 = 132 x $6.50 $858.00 In the work marked (a) the operation is explained. In practice, the work put down under (b) is all that is necessary. 30 FUNDAMENTAL OPERATIONS 10. The Sales Room sold to the Plain Sewing Divi¬ sion on November 21, 1910, the following: 51 yards of domestic at $.10 per yard; 1 paper of pins, $.05; 8 yards of sateen at $.15 per yard; and 55 yards of gingham at $.U8 per yard. Find total value of these goods. 11. In making a set of single wagon harness at the Institute Harness Shop, 16 pounds of leather costing $.38 per pound were used. Find the cost of the leather used for this purpose. 12. For making a set of light buggy harness, it is esti¬ mated that 15 pounds of oak harness leather are required. This leather cost $.40 per pound. Find the value of the leather in one set of such harness. 13. From September 1, 1910, to April 1, 1911, the Upholstery Division made 228 pillows. Each pillow re¬ quired 1 yard of ticking, $.15, and 4 pounds of linters at $.05 per pound. The cost of the thread, labor, etc., used in making each pillow was estimated to be $.10. Find the cost of making the pillows. 14. For the same period, 2011 pillow cases were made by the same division. In making each pillow case, 1 yard of pillow tubing, $.18 was used. The cost of the thread, labor, etc., required to make 1 pillow case was estimated to be $.06. Find the cost of the pillow cases. 15. On March 11, 1911, products of the Institute Truck Garden were sold on two vegetable wagons by students. The vegetables on each wagon were checked on the departure of the wagon and on its return. In this way, the amount of money to be reported by the driver was found. The following is the record of the two wagons on the day mentioned: MULTIPLICATION 31 Wagon No. 1. Wagon N o. 2. Out Back Out Back Turnip s 20 bunches, 6 bunches 12 bunches 3 bunches Salad (Rape) 10 3 11 0 " Onions 6 0 6 0 " Radishes 4 0 4 0 " Kale 4 2 '1 3 0 Rutabagas 10 0 S 0 " Sweet potatoes 3 bushels 3 pecks 2 bushels 0 bushels The sweet potatoes sold at $1.00 per bushel. The other vegetables at 5f per bunch. Find the value of the sales on each wagon and the total sales for the two wagons. 16. On one day the Truck Garden sold to the Board¬ ing Department the following: 24 bunches spinach (" $.05 12 bunches lettuce Ca> .05 75 bunches salad Ca) .02 7 bushels rutabagas On .80 10 bunches onions On .05 Find the value of the sale. 17. The J. W. Butler Paper Company of Chicago sold the Institute for use in the Printing Division 5 reams of paper, each ream weighing 140 pounds, at $.06 per pound. Find the cost of this paper. (What is meant by a "ream" of paper?) 18. The Institute bought of the American Linseed Oil Company 2 barrels of boiled linseed oil. One barrel contained 51 gallons and the other barrel contained 52 gallons. This oil cost $.75 per gallon. Find what the Institute paid the firm, a reduction of $1.55 being given for cash payment. 32 FUNDAMENTAL OPERATIONS 19. The Institute bought of the Loeb Hardware Com¬ pany of Montgomery 225 pounds of lamp black at $ 13 per pound and 5 gallons of paint at $2.25 per gallon. Find the cost of this order. 20. The Institute purchased from the Vandiver Gro¬ cery Company of Montgomery, Ala., the following: 2 bags of rice, 200 pounds, at $.06 per pound; 2 barrels of grits at $3.65 per barrel; 2 bags of Irish potatoes, 5 bushels, at $.90 per bushel; 3 cases of baking powder, 6 dozen cans, at $2.50 per dozen; 1 case of peas, 2 dozen cans, at $1.75 per dozen; 2 boxes of chocolate, 24 pounds, at $.33 per pound. The freight on the above was $1.66. Find total cost on the shipment. 21. During one month the Creamery bought from farmers living near the Institute 434 gallons of milk at $.18 per gallon. How much was paid for this milk? Find the products. 375X 4876 530X73632 904X 7083 900X 5362 7673 V 8219 906 < $ 37.87 537 x 406.09 872 X 5367.83 608 X 702.03 3117 X 4268.93 DIVISION Exercise 13 1. A uniform coat made in the Institute Tailor Shop had on it 5 buttons. In spacing the buttons on the coat, the tailor first located the top button, and then the bottom button. Measuring the distance from the top button to the bottom button, he found it to be 16 DIVISION 33 inches. He then located the other three buttons so as to make the distance between any two consecutive buttons the same. How far apart were the buttons on this coat placed? 2. On another coat made in the Tailor Shop there were placed 4 buttons. The distance from the first to the last button was 15 inches. How far apart did the tailor place the buttons on this coat? 3. A student in 'he Carpentry Division who received $.30 per day for his labor worked 7 hours on one day. H ow much did he receive for his work on that day? 4. A bolt of cloth received at the Dressmaking Division contained 42 yards. How many uniforms can be made from this cloth, allowing 8 yards to the dtess? How many yards would be left over? Give quickly the results. 12-^4 (read "12 divided by 4"). Here we are required to find the number which when multiplied by 4 will give 12. We know that 4X3-—12. Therefore, 12 -9— 4 = 3. 12, the number to be divided, is called the dividend. 4, the number by which we divide is called the divisor. 3, the result, is called the quotient. 15- - 3 12- - 6 18- - 3 16- - 8 14- - 2 24- - 6 20- - 5 22- -11 32- - 4 42- - 6 48- - 8 56- - 7 60- -10 63- - 7 72- - 8 88- - 8 77- - 7 99- -11 54- - 9 70- -10 81- - 9 96- -12 100- -10 64- - 8 49- - 7 28- - 4 60- - 5 34 FUNDAMENTAL OPERATIONS 36- 4 108- 9 36- 6 144-12 36-12 121-11 38 — 5. In this case, we see that we cannot find an integer which when multiplied by 5 will give 38. But we find that 7 is the number which when multiplied by 5 will give the product nearest 38. 5x7 = 35. 38 — 35 = 3. Then, 38 — 5 = 7, with 3 remaining. 3, that part of the dividend that is left, is called the remainder. 1. On one day 216 pounds of cream were churned at the Creamery. Find the number of gallons of cream churned on the day mentioned, allowing 8 pounds to the gallon. Since 1 gallon of cream weighs8 pounds, we shall have 1 gallon of cream for every 8 pounds that we have in 216 pounds. To find out how many times we have 8 pounds in 216 pounds, we divide 216 by 8 as follows: 8 will not divide 2 hundreds giving an integer 8)216 in the quotient, but will divide 21 tens, giving 2 tens 27 as quotient and 5 tens as remainder. Adding the 5 tens to the 6 units, we get 56 units. 56 — 8 = 7 Then, the quotient is 27. Therefore, 27 gallons of cream were churned on the given day. 2. Some painting done at Phelps Hall required *2 (one-half) gallon of white paint costing $1.90 per gallon and gallon of yellow paint costing $1.70 per gallon. Find the cost of the paint used on this job. (When a number is divided into two equal parts each part is called J/2 of the number.) 47 f 6 58-8 55-10 29- 9 32- 3 99-12 Exercise 14 $.95, cost of white paint. $.95 + $.85=$1.80, cost of paint for job. Note the decimal points in quotients. 2)$1.90 DIVISION 35 3. The Institute bought Ix3 (on< -third) dozen mor- ta hoes for the Brickmasonry Division for $2.00. Find the cost of one hoe. (When a number is divided into three equal parts, each part is called 13 of the number.) 4. Divide as indicated. 3872- 2 471- 3 5250 7761- 9 532- 8 7394 60832- 8 21252- 7 6372 84288-12 7340-10 6780 8453-16 5724-11 76394 6 5 4 10 10 Exercise 15 1. In January of one year 6,109 gallons of milk were received from the cows at the Dairy Barn. Find the average number of gallons received daily. To find the average number of gallons received daily for the month, we divide 6,109, the total number of gallons received during the month, by 31, the number of days in the month. The process of division is as follows: 197 Dividing 61 by 31, we obtain 1 as a quotient. 31)6109 1X31—'31. Subtracting 31 from 61, we get 30 as remainder. Bringing down 0, the next figure 300 in the dividend, we have 300 as the next partial 279 dividend. Dividing 300 by 31, we get 9 as a 219 quotient. 9X31- 279. Subtracting 279 from 217 300, we obtain 21. Bringing down 9, the next 2 figure in the dividend, we have 219 as the next partial dividend. Dividing 219 by 31, we get 7 as a quotient. 7X31 -=217. Subtracting 217 from 219, we obtain 2 as remainder. Then, 6109 gallons — 31 — 197 gallons, with 2 gallons as remain¬ der. Therefore, the average number of gallons received daily for the given month was about 197. The result of division when there is a remainder is generally ex¬ pressed thus: 6109-i-31 = 197"3T- FUNDAMENTAL OPERATIONS To check division, multiply together the divisor and <|uotient and add the remainder. If the result is equal to the dividend, the divi¬ sion is correct. In checking the division just performed, we pro¬ ceed as follows: 31 X 197 = 6107. 6107 + 2 = 6109. 2. The value of the work done in the Wheelwright Shop for one year was $4500. Find the average value of the work done per month. 3. Find the average daily sales of the Commissary for February, 1911. See Problem 12, page 17. 4. The sales of the Truck Garden products during the year 1910 were as follows: January, $849.13; Feb¬ ruary, $517.70; March, $667.47; April, $1010.26; May, $1201.26; June, $985.88; July, $1317.97; August, $857.03; September, $672.94; October, $701.96; November, $608.04; December, $301.48. Find the average monthly sales. 5. The record of the eggs laid by the chickens and ducks at the Poultry Yard for the week, January 24-30, 1911, is as follows: January 24 87 eggs 25 63 26 79 27 79 28 81 29-30 133 Find the average number of eggs laid per day. At this rate, about how many eggs were laid during the month? Di vide as indicated. 23079 — 39 40007-75 76552-96 17280-24 56258-54 90250:95 35008-48 22459-37 53659-76 98567^83 445445-89 72250 85 DIVISION 37 Exercise 16 1. In the summer of 1910, 397 dozen gallon cans of peaches were put up at the Canning Factory. This fruit was valued at $1885.75. What was the value per To find the value placed upon a dozen cans we divide $1885.75 by 397. Why? The process of division is the same as that given in Problem 1, Exercise 15. Note that the decimal point in the quotient is placed just above the decimal point in the dividend. 2. The Institute paid $10.80 as freight charge on a shipment of iron pipe from Birmingham, Alabama. This shipment weighed 4500 pounds. Find the freight rate per 100 pounds on this kind of goods. 3. The Institute received from Pheonix City, Ala., 4 barrels of syrup, each weighing 375 pounds. The freight rate on this syrup was $.20 per 100 pounds. What did the freight on this syrup cost the Institute? 4. A dealer sold the Institute 3000 eggs at $7 per 100. Find cost of eggs. 5. The Brickmasonry Division, in connection with some repair work, used the following material: 1300 bricks at $.79 per 100; 2 barrels of lime at $1.08 per barrel; 2 cubic yards of sand at $.80 per cubic yard; y barrel of cement at $2.60 per barrel. The cost of the student labor employed in the work was $1.44. Find total cost of the job. 6- A vault was built in a cemetery in the town of Tuskegee by students of the Institute. On this job were "used 12 sacks of cement at $.65 per sack, 2 cubic yards of dozen cans. $4.75 397) $1885.75 1588 297 7 277 9 19 85 19 85 FUNDAMENTAL OPERATIONS sand at $.80 per cubic yard, 2000 bricks at $.79 per 100. The cost of students' labor was $4.20, and $.25 was paid for hauling material. Find the cost of building the vault. 7. A car of coal received by the Institute contained 108,000 pounds of coal. How many tons of coal were in this car, reckoning 2000 pounds to the ton? 8. The total number of gallons of milk received at the Dairy Barn for the year 1910 was 59,590. Find the average number of gallons received daily for the year. Divide as indicated. 11025- 105 332869-- 367 3944384^ 563 6547328-7643 $1054.29^- 328 21280- 375 87621^ 998 2492963- 121 665417-9753 $6572.02^ 529 475000- 250 110032- 876 871061- 342 7061089-6431 $ 2983.53-4- 213 REVIEW Exercise 17 1. On a certain day there were 12 pounds of buttef on hand at the Creamery. On this day 66 pounds of but¬ ter were made and 14 pounds sold. On counting the but¬ ter before closing for the night, 63 pounds were found at the Creamery. Was all the butter accounted for? 2. On another day there were 60 pounds of butter on hand at the Creamery at the opening of business for the day. On this day, 62 pounds of butter were made and 59 pounds sold. On counting the number of pounds of butter left at the close of the day's business, 63 pounds were found. Was all the butter accounted for? 3. Find out (through teacher) the amount of butter on hand at the beginning of business, the amount made, the amount sold, and the amount found at the close of business on some recent day at the Institute REVIEW 39 Creamery. Then find out if all the butter was account¬ ed for on the day under consideration. 4. On January 1, 1911, the Creamery started a new record of the milk bottles taken from the Creamery by the drivers of milk wagons and of those brought back. The following is the record for January as kept at the Creamery. Route No. 1. Route No. 2. Date Out Back Out Back Jan. 1 43 48 22 17 " 2 45 49 73 28 " 3 58 68 21 14 " 4 51 42 24 22 " 5 41 53 10 10 " 6 45 • 53 22 20 " 7 52 65 18 17 " 8 53 5 26 27 " 9 40 41 23 25 " 10 55 60 26 20 " 11 53 51 23 25 " 12 48 44 27 13 " 13 44 60 19 26 " 14 62 52 26 23 " 15 43 47 19 17 " 16 39 45 20 16 " 17 41 46 16 " 18 63 52 25 19 " 19 46 47 18 21 " 20 54 48 18 " 21 51 60 17 5 40 REVIEW Route No. 1. Route No. 2. Date Out Back Out Back Jan. 22 77 95 32 29 " 23 92 77 30 34 " 24 76 77 29 29 " 25 72 100 29 24 " 26 91 88 34 36 " 27 95 79 30 31 " 28 75 94 33 32 " 29 81 59 36 34 " 30 61 74 32 27 " 31 81 65 30 30 H ow did the bottle account of Route No. 1 stand at the end of the month? Of Route No. 2? Of the Creamery? 5. The roof of the Dynamo Room was laid by the members of the Tinsmithing Division. The material used for this purpose was as follows: 14 boxes of tin roofing at $15 per box; 100 pounds of solder at $.20 per pound; G bundles of galvanized iron at $6 per bundle; 1 keg of nails, $3; 45 squares of roofing paper at $.35 per square; 1 gallon of acid, $.50; 15 bushels of charcoal at $.10 per bushel; 15 pounds of rosin at $.03 per pound. Drayage and freight on above cost $85. The labor em¬ ployed on this work cost $177.85. What did this roof cost the Institute? 6. The Institute paid $830 for 65 hogs. Find the average price per hog. 7. During the first three months of 1911, 27 hogs and 109 shoats, weighing in all 15,874 pounds, and valued at $.08 per pound, were slaughtered at the Institute. Find the value of these animals. REVIEW 41 The J. W. Butler Paper Co. of Chicago sold the Institute 10,000 shipping tags at $.85 per M (1000) and allowed a reduction of l/\ (one-fourth) of the given price. Find what the Institute paid the firm for these tags. 9. In October, 1910, 1329 students were fed in the Institute Dining Room at a cost of $5933.44. Find cost per student. 10. Six girls of the Senior Class of 1911 were commis¬ sioned to prepare a dinner for six persons at an expense of not more than $1.50. The material given to these students for the dinner follows: ice, $.15; lard, $.03; butter, $.14; flour, $.03; pickles, $.10; crackers, $.10; eggs, $.10; chicken, $.35; potatoes, $.05; peas, $.10; salt, $.02; sugar, $.15, bread, $.10; milk, $ 10. Material, valued at $.10, was not used. Did these students stay within expense limit? 11. The capacity of the Brewer brick machine at Brick Yard No. 1 is 20,000 bricks per working day of ten hours. How many bricks can be made by this machine in one hour? How many bricks can be made in a week, iunning full time? 12. In one kiln were burned 160,000 bricks. How many full working days must the machine have worked in order to turn out the bricks for this kiln? 13. The Institute shipped to the Burdell Floral Co. of Bowling Green, Ky. the plants as given below, the price per 100 being indicated in each case: 500 American can- nas, $1.50; 300 Boston ferns, $3.00; 200 mixed verbenas, $2.00; 100 whitmani ferns, $3.50; 200 coleus, $2.00; 200 42 REVIEW red geraniums, $2.50; 100 wandering Jews, $2.00. Find the value of the shipment. 14. The Institute bought for the Shoe Shop 1 roll of scoured oak leather. There were 10 sides of leather in the roll and 18 pounds to the side. Find the value of this leather at $.43 per pound. FACTORS AND MULTIPLES Exercise 18 1. Name two numbers whose product is 10. 2. Name two numbers whose product is 14. 3. Name two numbers whose product is 22. We find that the two numbers whose product is 22 are 2 and 11, These two numbers, 2 and 11, are called factots of 22. The factors of a number are the integers(whole num= bers) which when multiplied together produce the given number. Thus, 2X3X5 — 30; then 2, 3 and 5 are factors of 30. 4. Give three factors of 12. 5. Give three factors of 36. 6. Give five factors of 60. 7. Give two factors of 56. 8. Give three factors of 66. 2X3X11—66. Then 2, 3, and 11 are factors of 66. The num¬ ber, 66, which is the product of 2, 3, and 11 is called a multiple of each of those numbers. The product of two or more whole numbers is called the multiple of each of those numbers. Thus, 21 is a multiple of 7, because 7 is one of the factors of 21. 9. Give two multiples of each of the following num¬ bers: 8, 9, 10, 6, 17, 20, 19. 10. Give three multiples of 11. 11. Give all the multiples of 3 as far as 30. 44 FACTORS AND MULTIPLES 12. Give two multiples and two factors of 15. A number which can be exactly divided only by itself and 1 is called a prime number. A factor which is a prime number is called a prime factor. The following will be of assistance in finding the factors of num¬ bers: A number is divisible by 2 if it ends in 0, 2, 4, 6, 8. Thus, 74 is divisible by 2. (Numbers divisible by 2 are called even numbers. All other numbers are called odd numbers. ) A number is divisible by 3 if the sum of its digits is divisible by 3. Thus, 732 is divisible by 3, since 3 will divide 7^ 3 - 2. A number is divisible by 5 if it ends in 0 or 5. Thus, 985 is divisible by 5. Exercise 19 Give the prime factors of the following numbers'. 1. 210. The work may be arranged as follows: 2) 210 3) 105 5) 35 7 Then, the prime factors of 210 are 2, 3, 5, and 7. 2. 154 3. 165 4. 48 6. 247 7. 64 8. 100 10. 78 II. 108 12. 170 Exercise 20 1. Name a number that is an exact divisor of both 15 and 20. 2. Name a number that is an exact divisor of both 33 and 55. 5. 72 9. 230 13. 1728 FACTORS AND MULTIPLES 45 3. Name a number that is an exact divisor of both 24 and 42. An exact divisor of two or more numbers is called a common divisor of those numbers. The greatest number that will exactly divide two or more numbers is called the greatest common divisor of those numbers. 4. Give the greatest common divisor of 12 and 18; of 20 and 30; of 22 and 77. 5. Find the greatest common divisor of 60, 84 and 132. 60 = 2x2x3x5 To get the G. C. D. of these three 84 = 2 X2X3X7 numbers, proceed as follows: 1. Get 132 = 2x2x3x11 the prime factors of each number. 2. Write down the prime factors of the smallest of these numbers, 60. 3. Strike out all of the factors of 60 which do not occur in each of the other numbers. The product of the remaining factors will be the G. C. D. desired. Thus, putting down the factors of 60 and striking out the factor which does not occur in both 84 and 132, we have 2X2X3 Then, the G. C. D. of 60, 84, 132 is 2X2X3 or 12. Find the G. C. D. of the following numbers: 6. 90, 126 11. 128, 320 7. 48, 96 12. 56, 72, 104 8. 13, 26, 34 13. 118, 138, 280 9. 100, 350, 500 14. 112, 231, 306 10. 71, 81, 101 1. Name a number that is a multiple of both 3 and 4. 2. Name a number that is a multiple of both 6 and 10. 46 FACTORS AND MULTIPLES 3. Name a number that is a multiple of both 8 and 12. A number that is a multiple of two or more numbers is called a common multiple of those numbers. The smallest number that is exactly divisible by each of two or more numbers is called the least common multiple of those numbers. 4. Find the least common multiple of 4 and 6; of 5 and 12; of 9 and 12. 5. Find the least common multiple of 126, 294, 420. 126 = 2 X 3x3x7 To find the least common 294 = 2x3x7x7 multiple of these three numbers, 420 = 2x2x3x5x7 proceed as follows: 1. Get the prime factors of each number. 2. Writedown the factors of the largest number, 420. 3. Write down such factors of the other numbers as do not appear in 420. The product of all the factors thus written down will be the L. C- M. lequired. Thus, writing down the factors of 420, we have 2X2X3X5X7 In 126 there is one factor, 3, which does not appear in 420. In 294 there is one factor, 7, which does not appear in 420. Then, theL. C. M. of 126, 294, and 420 is 2X2X3X5X7 X 3 X 7 or 8820. Find the L. C. M. of the following numbers4. 6. 8, 20 12. 96, 144, 528 7. 16, 72 13. 13, 27, 61 8. 48, 108 14. 36, 108, 180 9. 144, 216 15. 55, 121, 143 10. 15, 60, 120 16. 42, 126, 378 11. 105, 150, 240 17. 11, 21, 35 COMMON FRACTIONS Exercise 21 Students to bring to class room pocket rule, ste el quare, tailor's or dressmaker s square, surveyor s tape, tape line—all avail¬ able instruments used in the trades for measuring length. 1. Point out on one of the measuring instruments mentioned above the inch, foot, yard. 2. Find the mark which divides the inch into 2 equal parts. What is each part called? 3. Find the mark which divides the inch into 4 equal parts. What is each part called? 4. Find the mark which divides the inch into 8 equal parts. What is each part called? 5. Students in trades requiring measuring instruments on which the inch is divided into smaller parts will report upon these instruments to the class. 6. How many inches in % of 1 ft? {%. of 1 foot means 1 ft.-f-4). 7. How many inches in h of 1 ft.? 8. How many inches in x/i of 1 yd.? 9. Find the number of inches in % of 1 yd. 10. Find the number of inches in of 2 ft. 2 ft. =2X12 in. = 24 in. 24 in.-^3=8 in. 11. Find the number of inches in % of 3 yd. 48 COMMON FRACTIONS 12. Find the number of feet in '4 of 4 yd. 13. Find the number of feet in of 4 yd. 14. Find the number of inches in 2 3 of 1 ft. 2 3 of 1 ft. means li of 1 ft. taken 2 times. Thus, -3 of 1 ft. = 2X ' 3 of 12 in. = 2X4 in. =8 in. 2 3 of 1 ft. is usually written ~ 3 tt. 15. Find the number of inches in M ft. 16. Find the number of feet in 23 yd. How does this result compare with the number of ft. in *3 of 2 yd? 17. Find the number of inches in -/i yd. 18. Find the number of pints in Y\ gal. 19. Find the number of ounces in 5 8 it). l/z , / 3, Y\ , %8, etc., are called fractions. The number above the line is called the numerator; the number below the line is called the denominator. Thus, in the fraction 23, 2 is the numerator and 3 is the de¬ nominator. If the numerator is less than the denominator, as in %, the fraction is called a proper fraction. If the numerator is greater than the denominator, as in 4, the fraction is called an improper fraction. % ft., as we have learned, may be regarded as ft. taken 3 times. ft. is called a fractional unit. Now, ft. taken 3 times gives 9 in. Also, % of 3 ft. is 9 in. Then, ft.=3X)^ ft■, and 34 ft.—3 ft.-: 4. From this we see that a fraction may be regarded in two ways: (1) as a fractional unit taken as many times as is expressed by the numerator, and (2) as an indicated division. When we think of as an indicated division, 3 is a dividend and 4 a divisor. In fact, division is often indicated by writing the dividend above the divisor in this way. Reduction of fractions 40 Read the following fractions and explain them in the two Ways mentioned above: Hit. i ft), I bu. s 7 4 t it, in. 32 4 gal. U in. U REDUCTION OF FRACTIONS Exercise 22 1. A bushel of corn weighs 56 pounds. How many pounds are in -/i bu. of corn? Multiply both numerator and denominator of this fraction by 2. Find the number of pounds in the result. How does this result compare with the number of pounds found in 34 bu.? 2. A bushel of beans weighs 60 pounds. How much does t bu. of beans weigh? Multiply both numerator and denominator of this fraction by 3. Compare the number of pounds found in the result with the number of pounds found in 5 bu. 3. How many inches in e yd.? Divide both numerator and denominator of this fraction by 2. Compare the number of inches found in the result with the number of inches found in i yd. 4. In a ton of coal there are 2000 pounds. How many pounds in H T.? D ivide both the numerator and the denominator of this fraction by 5. Compare the num¬ ber of pounds in the result with the number of pounds in IS 'T so 1 • From the preceding examples we have found that Multiplying or dividing both the numerator and the de¬ nominator of a fraction by the same number does not alter the value of the fraction> 50 COMMON FRACTIONS Exercise 23 1. Change 5 8 to a fraction whose denominator is 16. We see that the denominator 16 is 2 times the denominator 8. Then, s 2X5 x® 8 ~ o — 16. 2 x « Reduce the following fractions to equivalent fractions having the denominators indicated: 2 5 _... G 1 2 7. 7 8 — 6 4" 12 _4 3. 3 .. 8 " 3 2 8. 5 6 - 2 4 13. 2 9 4. 6 6 12 9. 5 8 ~ 2 4 14. 1 G 5. 3 2 — 1 2 10. 3 10 — 6 0 15. 8 8 ■ 6. 2 3 — 9 11. 1 4 1 6 16. T A fraction is reduced to its lowest terms when its nu¬ merator and denominator are prime to each other, that is, have no common factor except 1. Exercise 24 1. Reduce it to its lowest terms. _1 6 16-7-4 2 4 24 4 6 4 4 -f- 2 2_ 6 ~ 6 -f-2 3 Then, M—f 2 and 3 are prime to each other. it can be reduced immediately to its lowest terms by dividing the numerator and the denominator by their G. C. D., 8. Reduction of mixed numbers 51 Reduce the following fractions to their lowest terms: 2. 2 4 9. 4 8 16. A 3. 1 6 4 0 10. 1 3 1 6 17. y 4. 8 2 0 11. 1 4 1 (5 is. n 5. 1 8 2 4 12. 2 0 3 2 19. -h 6. 6 4 1 4" 4 13. 2 2 4 8 20. ^ 7. 5 6 14. 8 1 0 21. ^ 8. 1 2 l r> 15. 2 1 3 G 22. n REDUCTION OF MIXED NUMBERS On one day the Creamery sold 7 whole quarts of cream and 3/4 of a quart of cream. In the record at the Cream¬ ery, this quantity of cream was written 7qt., which means 7 qt. + -iqt. A number like7?4, consisting of an integer (whole number) and a fraction, is called a mixed number. Exercise 25 Reduce l-/\ to fourths. 1= T 7 7 X | / 2. 8_ I 3 — 3 1_ 4 I 4 4 -3 31 / 4 — 4 Change the following to improper fractions: 51 6i 4i 2f 8} 92 101 4g 3tV 7-i r, 141 12i 371 871 62i 16! 33-J 661 1U 81 llli 2H 14? 106 g 58U 99 z 00 oo 52 COMMON FRACTIONS Reduce V to a mixed number. VVe have learned that a fraction is an indicated division. Then, -i-1- means 11 : 4. Performing the division indicated, we get = 24 . 'Rjduce the following fractions to mixed numbers or integers: 1 6 3 3 3 2 1 2 10# 12 5 1 6 4 3__9 SLl 10 0 0 3 33 " "K " '7 ADDITION Exercise 26 1. Find the sum of i and t. ■|=4"5 The L. C. M. of the denominators, 4 1 , 3 and 5, is 15. Reducing each frac- s 15 tion to fifteenths, we find that +,• ■= 10,12 _2 2 17 10 ,4 12 15 + 15=15=11 5 1 5 , and 5—15. 10 fifteenths +12 fifteenths=22 fifteenths. Can you find the sum of | and without reducing each fraction to the same denominator? The L. C. M. of the denominators of two or more fractions is called the least common denominator (L. C. D.) of these fractions. Add the following fractions'. ADDITION 53 10. 11. 12. 13. l'^e, if 2~, e'4 14. A, ,;V.. -A- TC S - _7._ AO. 8 , 10, 40 16. The Institute bought of Carson Pirie Scott Com¬ pany of Chicago 8 bolts of gingham, the number of yards in the 8 bolts being as follows: 31J4, 31 ;4, 28/2, 31/2, 33-/i, 30>4 , 30, 32*2. Find the total number of yards of gingham bought. 311 = 311 311 = 331 281 = 281 311 = 311 331 = 331 301 = 301 30 =30 321 = 321 248V = 2511 To find the total number of yards purchased, we must add as indicated. The fractional parts of the numbers are first reduced to the least common denominator and added. The sum of the fractional parts of the numbers is the sum of the integers, 248 is 248 —|— 4 . - 248 + ^ = 2511. = 3f, or 3l. The result Then, The eight bolts of gingham contained 251 yards. 17. The number of gallons of whole milk sold by the Creamery on its two wagon March, 1911, is given below. routes for the month of Date Gal Ions Date Gallons Date Gal Ions 1 16-8 11 18 21 19 2 21 12 21 22 18 3 1858 13 20 23 17 4 18 14 20 24 16^ 5 19 M? 15 21 25 © C\) 6 17-. 8 16 21/2 26 19lA 7 19 K 17 18 h 27 15 8 17?4 18 19 28 18 9 22 19 23 29 18 10 20 20 145 o 30 17 31 16 COMVION FRACTION'S Find the total number of gallons of whole milk sold on the two routes during the month. 18. A skirt made in the Dressmaking Division was 39 inches long when finished. This skirt had one tuck requiring \ Vi inches of cloth and a hem requiring 3-H indhes. How long should the cloth have been cut for this skirt? 19. Another skirt was 38^2 inches long when finished. How long was the cloth for the skirt cut, if 1,'j. inches Were allowed for one tuck, 2 /2 inches for another tuck, and 4j'4 inches for the hem? 20. A uniform skirt made for a student in the Nurse Training School was 40 inches long when finished. This skirt had a 5-inch hem and two 2-inch tucks. L2 of an inch was allowed for turning the hem and 12 of an inch for a seam at the top. How long was the cloth cut for this skirt? 21. The sleevelets forming a part of the uniform just mentioned measured 8inches when finished. 2 inches were allowed for hem at each end and )\ of an inch for turn¬ ing each hem. How long was the cloth for each sleevelet cut? 22. At the Blacksmith Shop the rim of a wheel meas¬ ured 125 aft. How long a piece of iron was used for the tire of the wheel. -4 in. being allowed for welding? Add the following: 23. 7 J, 8h 24. 91, 7IsG 25. 121, 8fr 26. 13A, 175 27. 211, 13 L HI 28. 25tV, 102-, 331 29. 331, 181 f;, 24-,5o 30. 67? 451, 1071 SUBTRACTION 55 SUBTRACTION Exercise 27 1. From i take f The L. C. D. of the two fractions is found to he 24. Each fraction is reduced to 24ths and the difference found as indicated. Subtract as indicated. 2. 3 5 4 — 8 7. i 2 — 3 12. 1 5 3 2 4 — 16 3. 1 1 4 — 16 8. n 8" 13. 9 4 10 — 5 4. 7 3 16 — 8 9. 1-6 3 — 32 14. 3 3 3 4 0 — "4 5. 1 1 3 — 12 10. i 1 y — 6 4 ]5. s 1 9 — 6 6. 2 3 3 — 8 11. II — TT 16. 2 1 5 6 4 — 16 17. 121 — 9!. 121 = 111 =llfl Show that 12f=ll|. Why is 91= 91 = 9i®2 12~3 changed to 11-| before the 2 It subtraction is begun? Explain processs fully. 18. 13! -51 22. 40x6—22! 26. 561 -31/, 19. 25i -19A 23. 62,^- 17.2 27. 731 -151! 20. 100H-58U 24. 341 -171 28. 47H-39I 21. 981 — 76f 25. 6911-431 29. 18H-8II 30. Sugar that cost the Institute 5/8 f per pound was sold at the Commissary for 67/3^ per pound. Find the gain on one pound of sugar. 31. When a student was measured for a pair of trousers, at the Tailor Shop, the measurement for the out¬ side seam was found to be 42y?". The tailor deducted \l/i" for the rise in front and added Y\" for the fall in the back of the trousers. ?■]'{" was allowed for the hem. How long wa« the cloth cut in the front, at the outside seam, and at the back of the trousers? S6 COMMON' FRACTIONS 32. The measurement of the outside seam of another' pair of trousers was found to be 41 x'\". 1 1 -j " was de¬ ducted for the rise in front and added for the fall in the back and 2/4" was allowed for the hem. How long was the cloth cut in the front, at the outside seam, and af the back of these trousers? MULTIPLICATION Exercise 28 1. At the Institute Brick Yard, it is estimated that 3_t of a cord of wood is required to burn a thousand bricks. How many cords of wood were required to burn a kiln of 160 thousand bricks? If to burn 1 thousand bricks requires 3j- cord of wood, to burn 160 thousand bricks requires 160 times as much, or, 16(>X:1i cord. 160X3 fourths 480 fourths (44~) ---J- = 120. Then, it required 120 cords of wood to burn the kiln of 160 thousand bricks. 2. According to the preceding problem, give a rule for finding the product of an integer and a fraction. The process of multiplying, when one of the facto.s is a fraction, can often be shortened by first indicating the product and then canceling, that is, striking out the common factors in the dividend (numerator) and divisor (denominator.) Thus, 40 160X .3='«X3 = 4qx3 = 120 In this case the common factor 4 is struck out of 160 and 4. Upon what principle does cancellation depend? Multiplication 1 he Institute bought for the Shoe Shop from the Atlanta Leather Company three calf skins, the total weight of which was 6-4 pounds. This leather cost $1.35 per pound. How much did the Institute pay the firm for the leather? $1.35 To find the amount paid for the leather, we multi- 6 >4- P'y $T35by6'\\. Why? 810 6X$1-35=$8.10 101 Ti , r 3X$1.3S " $4.05 ^ 1 1W1 4 4X$1-3S = —-7^ — = - — $1.0li •$'9.11 K . 64 X $1.35 = $8.10 +$1 .OtI = $9 11-4 Then, the Institute paid the firm $9.11 for the leather. 4. At the Institute Harness Shop, 17 pounds of harness leather valued at $.35 per pound were used in making a set of medium buggy harness. Find the value of the leather used in making this set of harness? 5. In making some crates for the Piggery, the Carpen¬ try Division used $2.77 worth of material. On this job three workmen were employed. One hired man worked 7/^ hours at $.25 per hour; another hired man worked 3Y hours at $.25 per hour; one student worked 5 hours at $.05 per hour. Find total cost of job. 6. The materials used in making a suit at the Tailor Shop were as follows: 3/4 yd. of black unfinished worst¬ ed at $3.00 per yd.; 1% yd. of black Italian lining at$1.24 per yd.; 1Y yd. of silk sleeve lining at $.55 per yd.; 34yd. of vest lining at $.45 per yd.; 1 yd. of shrunk linen duck at $.24 per yd.; 1 yd. of wire cord silesia at $.19 per yd.; 1 yd. of wigan at $.11 per yd.; ^ yd. Holland (linen) at $.25 per yd.; Y\ yd. of padding at $.65 per yd.; l/i yd. of hair cloth at $.40 per yd.; H yd. of twill pocketing at 58 COMMON FRACTIONS $.21 per yd.; Y- yd. of waist band canvas at $.21 per yd. The buttons used were estimated to be worth $.15. Find total cost. 7. During November, 1910, a girl in the Dressmaking Division finished 4 pieces of work for which she received $.12 Y a piece. How much did the student earn in this way for the month? $ 12 By multiplying $.12^ by 4, we find the amount received by the student for the 4 pieces of work. 48 4X12^=4X 7^+4X12 $.50 4X^=2;4X12 = 4S Then, 4X12^=2-^48 = 50. 8. The uniform waist worn by the Institute girls in the spring of 1911 cost as follows:. 8 yards of madras at $.08>2 per yard; buttons, $.08; thread $.02X1; labor, $.25. The waists were sold for $.65. Find gain on each waist. 9. The uniform skirt of a girl made in the Dressmak¬ ing Divis'on required 5 yards of percale at $.12/2 per yd. Other items of expense in connection with the making of the skirt were: 1 spool of thread at $.05; 2 hooks and eyes, $.01; four (Vs dozen) buttons at $.10 per dozen; the labor of one girl 9 hours at $.03 per hour. The skirt sold for $1.00. Find the gain on this skirt. 10. In making a shirt waist, 2/2 yards of lawn at $.20 per yard were used. On this same waist, there were used 1 dozen buttons, $.10; 1 spool of thread, $.05; and 2 yards of lace at $.15 per yard. The cost of making the waist was $.35. Find the total cost of the waist. 11. The hats worn by the Senior girls in 1911 were made in the Millinery Division. Each hat required the MULTIPLICATION following: 3 bolts of straw at $.62per bolt; 134 yards of silk at $.50 per yard; wire, $.15; cheese cloth, $.08; thread, $ 03. Find total cost of materials used in making one of these hats. 12. The Tinsmithing Division made two refuse boxes for use in the Boarding Department. Each box requir¬ ed 1/4 sheet of galvanized iron. Each sheet of such iron Weighed 40 pounds. This iron cost $.04 per pound. To make one of these boxes required the labor of one student 5 hours at $.03Y?. per hour. Find total cost of the two boxes. 13. On one day six students worked 5 hours staining some railing in the Shoe Shop. Three of these students received $.02 Y per hour; one student received $.03 Y* Per hour; each of the remaining two students received $.02 per hour. The gallon of stain used on the job cost $1.60. Find total cost of the work. 14. The House and Sign Painting Division in some work done at the Poultry Yard Used the following: 2 gallons of gray paint at $1.70 per gallon; 2 gallons of slush paint at $1.00 per gallon; 1 gallon of No. 7 paint at $1.70. On this job were employed 3 students 4/4 days, each at the rate of $.50 per day, and 1 man Y* day at the rate of $2.50 per day. Find cost of the job. 15. To "hard oil" some woodwork in Cassedy Hall 'required 1Y2 gallon of hard oil at $1.70 per gallon. Y\ gallon of turpentine at $1.00 per gallon, and one box of Washing powder, $.05. The labor employed in this work cost $2.10. Find cost of work. 16. The Institute bought for the Printing Division 12 reams of paper, each ream weighing 75 pounds at $.06><4 per pound. Find cost of paper. fr'O COiVhMON FRACTIONS 17. The Institute shipped to the Virginia Nursery- Co., Purcellville, Virginia, the following plants: 100 sal¬ vias at $.02 each; 75 verbenas at $.02 each; 50 white ge¬ raniums at $ 02/^ each; 25 red geraniums at $.02/2 each; 75 coleus at $.02 each. Find the value of this shipment. 18. The Creamery has two wagon routes on which it sells dairy products to its customers. On Route No. 1, two trips are made daily. At the beginning and end of each trip, the products in the wagon are checked and the quantity recorded. The following is the record of the two trips made by the wagon on Route No. 1 on April 3, 1911. Morning Aft ernoon Out Back Out Back Whole milk Gallons 7 2 Quarts 12 1 9 5 Pints 3 10 1 Halves 4 1 10 1 Cream Quarts 2 l'/s 1 X Skimmed milk Gallons 15 4 Buttermilk Gallons 9 Butter Pounds 8 3 4 On this route the price of the whole milk was as follows: gallons, $.28; quart, $.07; pint, $.04; half pint, $.02. The cream sold at $.40 per quart; the skimmed milk, at $.08 per gallon; the buttermilk at $.10 per gallon; the butter at $.28 per pound. Find the value of the sales on this route for the given day. MULTIPLICATION 61 19. In the shop of the M attressmaking Division, double mattresses are made 6 ft. 4 in. long and 4 ft. 6 in. wide. In estimating the amount of cloth to be used, for every foot and fractional part of a foot in the length, in. is to be added for tufting. The same addition is to be made to the width. The border (boxing) is cut 5 in. wide. In making one such mattress ticking 30 in. wide and costing $.15 per yard was used. There were also used 45 pounds of linters (cotton) at $.04 per pound, 5 pounds of corn shucks at $.02 per pound, and tv\ ine, $.05. One girl working one day for $.25 made the complete mat¬ tress. Give drawing to show how you would cut the cloth. Find the cost of producing the mattress. 20. A single mattress made in the shop mentioned above measured 6 ft. 4 in. long and 2 ft. 9 in. wide. The following materials were used in making this mattress: 20 pounds of linters at $.04 per pound; 5 pounds of shucks at $.02 per pound; twine, $.03. The boxing (border) was cut five inches wide. The ticking used cost $.15 per yard. One girl worked ^2 day at the rate of $.25 per day in making the mattress. Making allowances for tufting as in the preceding problem, find the cost of producing this mattress. Exercise 29 1. Find a scale (on steel square, tailor's square, pocket rule, or other instruments) in which % in. is divided into 3 equal parts. Counting the number of such parts in 1 inch, we find that in 1 inch, there are 12 such parts. Each of these parts is iV of an inch. Then, 3 of = , or what is the same thing, i \/ i// X—H 3X4 — 12 COMMON FRACTIONS Suppose that we are required to find § X 5« that (s, § of I". Now, we have already found that -1- v -1" 3X4 ^ L-// — 12 • Since 2 3 X CM Jl — v ? 3 X 4 X CM II Since II CO X iXT" = 3Xtt" Since u-fxl, we see that To multiply one fraction by another fraction, we multiply the two numerators together and the two denominators together and write as result the product of the numerators over the product of the denominators. Give the products indicated. Cancel whenever possible. 2. k x6. 3^x1 10. Hx -! 3. fx! 7. tVXt 11. ifx 4 4. ixif 8. Axt 12. IX~h 5. TeXf 9. Hxt 13. 11X It 14. 5/^x7^ (Reduce each mixed number to an im¬ proper fraction before multiplying). 15. 51 x 61 19. lOA- Xll 16. 91x31 20. 51 x3! 17. 4-Hrx-t- 21. 2 bolts at $1.12/4 per bolt; thread, $.08^ ;velvetband, $.37/4; 5 yards of silk ribbon at $.40 per yard; 2 hat pins at $.37/4 each; labor of one student, 2 days at $.25 a day. This hat was sold for $7.85. Find gain. 27. An individual sold the Institute for use in the Canning Factory 2/4 pecks of figs at the rare of $.50 per bushel. Find what was paid for these figs. 28. The Institute bought at one time of Schloss & Kahn of Montgomery, Alabama, 250 pounds of oats at $.62/4 per bushel, and 500 pounds of oats at $.44 per bushel. Reckoning 32 pounds of oats to the bushel, find the total cost of the above purchase. Exercise 30 1. On one day 900 pounds of cotton seed meal were used at the Dairy Barn as part of the feed for the cows. Find the cost of this meal at $27.00 per ton. 2000 pounds =1 ton 1 pound = 2_oVo" ton 900 pounds = 900 X 2~oV"o ton = 2% ton The cost of 1 ton of meal =$27.00 Then, the cost of 2% ton of meal = 2S-X$27.00 = $-2-~! In fact, the reciprocal of any number is 1 divided by that number. Thus, the reciprocal of 8 is "g". We see from the above that To divide a fraction by an integer, multiply by the reciproc- tal of the integer. 66 DIVISION 8. 5 9. tW 4 10. 31 . 7 64 — / 11. 6 12. A-5-14 13. ii Divide as indicated. Cancel when possible. 2. } -2 3. I -4 4. I -2 5. i%-5 6. ! -3 7. f — 4 14. 5T/3—8 (Red uce mixed number to improper frac¬ tion before dividing). 15. 91-11 19. 121- 7 16. 7f — 5 20. 33i —10 17. 31- 9 21. 151- 3 18. 8f —4 22. Ill- 8 23. 216J-5 Without reducing 2161 to an improper fraction, the work may be performed as follows: 5)216f 216 — 5 = 43, with 1 as a remainder. 43Vff U-5=txi = 27o 24. 1121 25. 3761 26. 501f 27. 100^ 28. 2111 29. 7061 30. 143i 31. 3607^ 3 9 12 4 32. At the Institute Tailor Shop in locating the but¬ ton holes upon a coat, the tailor first decides upon the location of the first and last buttons. On a uniform coat made in the shop, the distance from the first button to the last was found to be 1Z1/?". There were five buttons on this coat, the distance between any two successive buttons being the same. How far apart were the buttons placed on this coat? COMMON FRACTIONS 13. On another uniform coat the distance from the first to the last button was 14?4"> There were 5 buttons on this Coat. Find how far apart the buttons were placed. 14. On a three-button coat, the distance from the first to the last button was 11/4 inches. Find how far apart the buttons were placed. 15 On another three-button coat, the distance from the first to the last button Was 10 v/\ inches. How faf apart were the buttons placed? 16. In a two-horse wagon made in the Institute shops the width of the bottom of the body was 41%//. The front cross bar was 47// long. The bottom was nailed to the front cross bar so as to be the same distance from each end of the bar. Find the distance from the end of the bar at which the mechanic should begin to nail the bottom. See wagon. 17. Find out (through teacher) what is a mortise and tenon joint. At the Wheelwright Shop, in making a wheelbarrow, it Was necessary to locate a Vb" mortise in a 2" handle. Show how this mortise is located. 18. On the 1/4" sill of a wagon there is a }4" mortise. Explain how this mortise is located on the sill. 19. Secure (through teacher) other examples of mortise and tenon joints from the actual Work of the In¬ stitute Shops. Show in each case how the mortises and tenons are located. Exercise 32 1. A student in the Wheelwright Division was given a working draft (drawing) of a milk wagon according to 68 DIVISION which he was to build the wagon. On this drawing Y\ in. represented 1 ft. The width of the door of the wagon appeared as 1^2 in. How wide did the student actually make the door of the wagon? If Mm. on the drawing represented 1 ft., then, for every >4 in. in l/^in. there was 1 ft. in the actual width of the door. To find the width in ft. of the door, we must divide 1 ^2 in. by ~/\ in. II . 3 3 . _3 ±2 -r- 4 = 2 — 4 Since 1 — 4 , l-j-4: = 4, and l-f = iof 4=! 2 3 3 3,43 4 Then, 2 - 4"~ 2 3 ~ f X 3 The actual width of the door of the milk wagon was 2 ft. We see from the solution of the preceding problem that To divide a fraction by a fraction, invert the terms of the divisor and multiply. 2. The height of the same door was represented on the drawing by 2Y\ in. Find the height of the door. 3. On the working draft of a mail wagon built in the Institute Shops, the length of the wagon was represented by 10/^ in. and the width, by in. On this drawing, 1/4 in. represented 1 ft. Find the length and width of the mail wagon. 4. The Institute bought for the Paint Shop 379 pounds of linseed oil at $.89 per gallon. Find the amount paid for this oil, reckoning 7/^ pounds of linseed oil to the gallon. 5. The Mattressmaking Division received two bolts of white sheeting, one consisting of 41/2 yards and the other, 34 yards. Find the number of sheets that were made from this sheeting, 2/4 yards being used for each COMMON FRACTIONS 69 sheet. Find the cost of each sheet, if the sheeting cost $.23 per yard and the thread, labor, etc., cost $.10 per sheet. 6. The Printing Division made 500 letter heads, measuring 8/^'Xll", for use in one of the offices in the Institute. The paper from which these letter heads were cut came in sheets 17//X22// weighing 20 pounds to the ream, and costing $.14 a pound. How many sheets were used in making the 500 letterheads? Find the cost of the paper so used. Make drawing to show how the sheets were cut so as to have no waste. See specimen of paper furnished by teacher. 7. Daily record blanks made by the Printing Division measured 8^2//Xl4.// The sheets from which these blanks were cut were 28" long and 11" wide, weighed 20 pounds to the ream, and cost $.10 per pound. Find the cost of the paper used in making 2500 of the record blanks. 8. The absent and tardy blanks used in the Academic Department in 1911 measured . Th ese blanks were cut from stock measuring 17//X22.// This paper weighed 16 pounds to the ream and cost $.08 per pound. Find the cost of the paper used in filling an order for 10,000 of these blanks. 9. The paper kept in stock at the Printing Office on which The Southern Letter is printed measures 24//X36,// weighs 70 pounds to the ream, and costs $.08 per pound. Measure a copy of The Southern Letter and compute the cost of the paper required by an issue of this monthly for which 15,000 copies were printed. 10. M easure one of the monthly statements given to students of the Institute. Secure (through teacher) sufficient information from the Printing Office to allow you to compute the cost of the paper in lU,000 of these blanks. 70 common fractions Exercise 33 1. A reduction of %. of the list price was given ofl some goods purchased by the Institute. The amount paid for the goods Was $300.15, What was the list price of the goods? The Institute paid ^4 of the list price for the goods. Explaifi. 34 of list price of goods = $300.15 34 list price of goods = "3 of $300.15— $100.OS T of list price of goods — 4 X $100.05 = $400.20. Then, the list price of the goods was $400.20. What is meant by the "list price" of goods? 2. The weight of 1 cu. in. of cast iron is about if of the weight of 1 cu. in. of wrought iron. A piece of machinery cast at the Foundry weighed 97^3 pounds. What would the same piece of machinery weigh if made of wrought iron? 3. The threaded Dart of a screw is y%" long. On this Screw there are 28 threads. How many threads are there on a screw of the same kind whose threaded part is V long? 4. Another screw whose threaded part is long has 10 threads. How many threads are there on a screw of the same kind whose threaded part is V long? 5. If "H- of a number is 121, what is the number? 6. If tV of a number is 75, what is the number? 7. If ~T2 of a number is 4.0/4, what is the number? 8. If f of a number is 23%, what is the number? 9. If iV of a number is 2, what is the number? 10. If I of a number is /3, what is the number? AREAS AND VOLUMES AREAS Using the steel square or the dressmaker's square, draw on the board a figure of four sides, making each side 1 foot long and taking care to "square" each corner by means of the instrument. Such a figure, having four equal sides and four square corners (right angles) is called a square- The amount of surface in this figure is called 1 square foot. Just as cloth is sold by the yard, coal by the ton, milk by the gallon, etc., so certain other goods are sold by the square foot, as, the slate blackboards in the Academic Building, the stained glass in the windows of the Chapel, and certain kinds of leather used in the Harnessmaking Division. A figure, like the drawing below, which has four sides and four right angles (squared corners) is called a rectangle Is a square a rectangle? | This figure represents a rectangle 4 feet long and 3 feet wide. ( % in. rep- resents 1 foot.) The horizontal lines ' divide the rectangle into three strips each 1 foot wide. The vertical lines divide each of these strips into 4 square feet. Then, there are, in all, 3x4 sq. ft. or 12 sq. ft. in the rectangle. The number of square units—square inches, square n areas and volumes feet, etc., in any figure (surface) is called the area of that figure. Thus, ift the above figure, the area is 12 square feet. The area of a rectangle is given by the product of the numbers that express its length and width in the same units. 1 he length and width of a rectangle are called its dimensions. Exercise 34 1. A piece of calf skin in the Shop was fouftd to DC 48" long and 30" wide. This leather cost $.40 per sq. ff» Find the cost of the piece of calf skin. 48" = 4' 30" *= l\' 4X2*2 X 1 s<|. ft. — 10 sq. ft., the area of the skin. Since 1 sq. ft. of this leather cost $.40, then 10 sq. ft. of the leather cost 10X$-40 or $4.00^ Therefore, the piece of calf skin cost $4.00. 2. Measure the slate boards in Room 24, Academic Building. This slate cost $.16 per sq. foot. Find the cost of the slate out of which the boards of this class room are made. 3. The back of a buggy seat built in the Institute Shops measured 18"x30". In cutting the leather for this back, there were added to the length 9" for pleating and 6" for finishing; there were added fo the width 6" for pleating and 5" for finishing. This leather cost $.27 x/i per sq. ft. Find the cost of the leather used for this back. 4. The seat cushion of the same buggy was 28" long and 17" wide. In cutting the leather, there were added to the length 8" for pleating and 4" for the finishing; AREAS AND VOLUMES 73 thefe were added to the width 5" for pleating, and 5" for finishing. The leather of which this seat cushion was made was the same as that mentioned in the preceding problem. Find the cost of the leather used for this cushion. 5. The dash board of the same buggy was 20" long and 16" wide. Both sides of a dash board are covered with leather. In Cutting the leather for each side, 2r> Was added to the length and 4" to the width for finish¬ ing. Find the Cost of the leather used to cover the dash board, this leather being worth $.25 per sq. ft. 6. Class will visit Carriage Trimming Shop and esti¬ mate cost of leather used in trimming a carriage in the shop at the time of visit, 7. To find the cost of the flooring of a room, proceed as follows: Find in square feet the actual area to be covered; then add to this result %. of the area found. This gives the number of sq. ft. of lumber required. Find the cost of the lumber required to floor your class room at current prices. 8. Secure (through teacher) information concerning the method used at the Institute in estimating the cost of plastering. Compute the cost of plastering your class room. VOLUMES Examine one of the ordinary bricks made in the Insti¬ tute Brick \ ard. How many measurements are necessary to give you an idea of the size of the brick? How many measurements are necessary to give you an idea of the size of orte of the faces of the brick? A solid of the shape of a brick, all of Whose faces are rectangles, is called a rectangular solid. 74 AREAS AND VOLUMES In estimating the cost of the brick-work in a given structure, it is, of course, necessary to know the number of bricks required. One method used by brickmasons is to reckon a certain number of bricks to each cubic foot of the structure to be built. We shall now proceed to find out what is meant by a cubic foot. Observe the cubic foot of wood exhibited by teacher. How many edges has it? Measure the length of each edge. What figure does each face make? What is the area of each face? Every solid of this shape is a cube. Then, what is a cube? What is a cubic inch? A cubic yard? Construct by means of wooden cubic inches (supplied by teacher) a rectangular solid that is 5" long, 4" wide, and 3" high. You thus obtain a rectangular solid with 3 layers of cubic inches. Each layer contains, as you can find by counting, (4x5) cu. in., or 20 cu. in. Then, the three layers contain (3x4x5)cu. in., or 60 cu. in. The number of cubic units—cubic inches, cubic feet, etc., in any solid is called the volume of the solid. Thus, the volume of the solid just constructed is 60 cu. in. The volume of a rectangular solid is given by the product of the numbers that express its length, width, and thickness in the same units. The length, width, and thickness of a rectangular solid are called its dimensions. AREAS AND VOLUMES 75 Exercise 35 1. At $7.90 per M ( 1000), what is the cost of the bricks in one of the walls of White Memorial Hall that is 20' long, 18" thick, and 20' high. Count 22 bricks to 1 cu. ft. 18"^ ii' 1^X20X20X1 cu. ft. —600 cu. ft., the volume of the wall. 600X22 bricks = 13,200 bricks. 13,200 ^-1000^ 13^, the number of thousand bricks in 13,200. l3iX$7.90 = $104.28. cost of 13| thousand bricks. Then, the bricks in the wall cost $104 2$. 2. The truss plates used in the construction of Tomp¬ kins Hall were cast at the Institute Foundry. Each plate is 2"x22"x28." One cu. in. <>f cast iron weighs about U of a pound. At $.02 a pound, what is the value of one of these plates? 3. The four foundation plates for the Institute Watef Tank were also cast at the Foundry. Each plate meas* ures 2"x28"x28." At $.02 a pound, what is the value of the four plates? 4. The frame for- a manhole Cast at the Foundry measured i"X26"X26." Find the cost of this frame at $.02 per pound, deducting 186f cu. in. for the hole in the frame and adding 20 pounds for the lip of the frame. 5. What is the cast iron mentioned in the preceding problems worth per cu. ft ? 76 AREAS AND VOLUMES 6. How many cu. in. in a 16-pound sash weight cast at the Foundry? If such a mass of iron were cast in the form of a rod 2" square at the ends, how long would the rod be? 7. Find out (through teacher) the dimensions of a pattern of simple shape recently cast at the Foundry, and estimate the value of the same. 8. A farm wagon built in the Institute shops had a bed 1' 6" long, 3' 2" wide, and 10" high (inside measure¬ ments). Find the capacity of this wagon in cu. ft. How much does it lack of holding a cu. yd.? 9. Another wagon had a bed 8' long, 3' 2" wide, and 15" high. By how much does its capacity exceed 1 cu. yd.? 10. Class will visit the Wheelwright Shop and compute from actual measurement the capacity of wagons under construction. REVIEW Exercise 36 1. The Senior girls in Practice Cottage used the fol¬ lowing supplies for the week beginning Dec. 30, 1910: 2 pounds of pork at $.12i per pound; 2 dozen oysters at $.10 per dozen; 2 cans of pears at $.25 a can; 1 pail of lard, $.35; 10 pounds of sugar at $.062" per pound; 1 quart of syrup, $.10; 1 box of corn flakes, $.10; 1 dozen eggs, $.30; 1 cake of chocolate, $.25; 1 bottle of flavoring, .$05; 1 peck of potatoes, $.35; 1 sack of flour, $.40; i peck of meal, $.25; 1 \ pounds of bacon at $.20 per pound; 1 chick¬ en, $.40; 2" dozen onions, $.10; 3 bars of soap at $.05 each; 1 broom, $.40; 1 gallon of oil, $.15; 1 box of starch, $.05; 1 box of bluing, $.05; 2 cans of tomatoes at $.08 each; 2 cans of peas at $.071 each; 1 box of macaroni, $.07. Find the cost of these supplies. 2. On one day, 400 dozen biscuits were made in the Bakery. In making these biscuits, the following materials were used; 280 pounds of flour at $.03i per pound; cans of milk, 10 gallons to the can, at $.08 per gallon; 5 pounds of salt at $.01 per pound; 40 pounds of lard at $.12 per pound; 10 pounds of baking powder at $.11 per pound. Find the cost of the materials used in making the biscuits. 78' REVIEW 3. The standard sizes of flat paper used in the Print-- ing Division are given below. The numbers give the width and length in inches. Flat Foolscap 13X16 Cap 14 X ^ Crown 15X19 Demy 16X21 Folio Post 17 x 22 Medium 18x23 Double Flat Foolscap ......16x26' Royal 19 x 24 Double Cap 17x28 Super Royal...... . 20x28 Double Demy 21x32 Double Demy, Oblong 16X42 Imperial ... -^3x31 Double Medium 23 x 26 Double Medium, Oblong 18x46 Elephant 23 x 28 Colombier • ■ ■ ■ 23 x 34 Atlas , ,••••' 26 x 33 Double Royal 24 x 38 Double Elephant "....27x40 Antiquarian! . ... '. 31 X 53 Secure specimens of the letter heads, blanks, etc., used in the various departments of the Irfstitute. In each case find out by actual measurement the size or sizes of paper named above from which the letter head or blank can be cut without Waste. Make drawings to show how you would cut the paper. 4. The Cudahy Packing Co., Memphis, Tenn., sold the Institute 150 pounds of bacon at $.10i a pound; 125 pounds of shoulders (pork) at $.111 a pound: 688 pounds of lard at $.08f a pound. Find total amount paid for these supplies. REVIEW 79 5. The Institute bought for the Truck Garden 50 bushels of seed potatoes at $1,872 per bushel. Find the cost of these seed potatoes. 6. Th ree bales of broom corn were purchased by the Institute. Two of these ba es, weighing together 650 pounds, cost $.07y per pound; the third bale, we ghing 372 pounds, cost $.061 per pound. Find the amount paid for the three bales of broom corn. 7. A piece of calf skin in the Shoe Shop contained 7//2 sq. ft. If a pair of uppers for shoes requires 2/^ sq. ft. of leather, how many pairs of uppers can be cut from this piece of calf ^kin? 8. It is estimated that for each pair of half soles for women's shoes, a piece of leather Syi" X7is required. How many pairs of half soles of this kind can be cut from a piece of leather ll"X60/;. Make drawing to illustrate your result. 9.. At $.16 per Sq. ft., find the amount paid for the slate boards of Room 12, Academic Building. 10. An estimate was made at the Carpentry Shop on the cost of flooring 2 rooms and a hall of a house in the town of Tuskegee. Each of the rooms measured 16/X20/; the hall,12/x34/. The flooring specified in this estimate cost $2.40 per 100 sq. ft. The moulding for each room and the hall cost $.50 per 100 feet. (In finding the amount of moulding needed, the entire distance around each room and the hall was counted.) Other items in the estimated cost were: 50 pounds of nzils, $.1.75; sand paper, $.50; labor, $1.50 per "square" 80 REVIEW of floor laid (1 square = 100 sq. ft.). For supervision and waste, tV of the cost of the above was added. Find total cost of job according to this estimate. (See Problem 7, Exercise 34.) 11. The Institute bought of the Pittsburgh Plate Glas9 Co. of Atlanta the following pieces of stained win¬ dow glass: 16 lights, each 13" Xl8"; 50 lights each 14" X 36". This glass sold at $.10 per square foot. Find the value of the order. 12. Find the cost of the following materials used in the Carriage Trimming Division in making the back of a buggy: 1 piece of leather, 30" X45" at $.21 per sq. ft.; 1 piece of buckram, 30" long, at $.42 per yard; 1 piece of sale duck, 16" long, at $.65 per yd.; Yi yd. mole skin at $.50 per yd.; 40 clinch buttons at $.30 per gross. 13. A tank made at the Tin Shop measured 24" X 24" X 30". Find the number of gallons that it will hold (231 cu. in. to 1 gallon). 14 A cheese vat made for the Creamery in the Tirf Shop measured 12"X 23" X42". Find the capacity of this vat. 15. The inside measurements of a wagon bed built irt the Institute shops were 16" X40^2 "X9' 8". Find the capacity of this wagon bed in cu. ft. How much does this wagon lack of holding 2 cu. yd.? DECIMAL FRACTIONS The Institute pays the freight charges on most ship¬ ments of goods purchased by it. At one time a barrel of linseed oil was received from St. Louis and the freight charges paid by the Institute amounted to $1,046 for every 100 pounds in the weight of the barrel. Now, as we have already learned, the figure 4 gives the number of cents in the amount of the money mentioned. The figure 6 states thenumber of milts. (10 mills —1 cent.) What part of a dollar is 4 cents? What part of a dollar is 1 mill? What part of a dollar is 6 mills? On a shipment of corn from Montgomery, Ala., the In¬ stitute paid freight charges at the rate of $.099 per cwt. (cwt. is the abbreviated form of hundred weight, which means 100 pounds). What part of a dollar does the 9 next to the 0 express? What part of a dollar is expressed by the 9 on the right? How does the amount expressed by the first 9 compare with that expressed by the second 9? 82 DECIMAL FRACTIONS At the Machine Shop, it is estimated that 1 cu. in. of wrought iron weighs .2816 lb. (read "two thousand eight hundred sixteen ten-thousands"). In this number, .2816ft)., the figure 2 expresses i^oft)., the figure 8 expresses too"ft)., the figure 1 expresses ToVofb., the figure 6 expresses tooooR). Then, .2816 = i%^too^toVo"-I-totot i W2 15. 1000x52.304 21. 94.737x5.067 16. 1000x1107.0325 22. 70.008x3.005 17. 10000x376.942 23. 4.01^X7.32-^ DIVISION 1. Divide 120 by 8. Multiply both dividend and di¬ visor by 6, and then perform the division. Multiply both dividend and divisor by 10 and then perform the division. 2. How does multiplying both dividend and divisor by the same number affect the quotient? 3. In one month a cow at the Dairy Barn gave 670.8 pounds of milk. Find the value of this milk at $.19 per gallon. (8.6 1b. make 1 gallon). DIVISION 93 To find the number of gallons in 670.8 pounds, we divide 670.8 by 8.6. Before dividing, we multiply both dividend and divisor by 10. Thus, 10X670.8=6708, and 10X8.6=86. Now, 670.8^8.6 = 6708 -86. Why? 78 Checking result, we find that 86^fino8 78X8.6 = 670.8. ~7^,0 Then, in 670.8 lb. of milk there are 78 gallons, boo ggg 78x$. 19 = $14.82. Therefore, the value of the milk given by the cow during the month was $14.82. 4. Divide 3.5154 by .93. Here we multiply both dividend and divisor by 100. This multiplication we know, will make the divisor an integer. 100x3.5154 = 351.54. 100 x.93 = 93 3.78 3.5154-.93 = 351.54-93. Why? 93)351.54 Explain the division as indicated. 279 Account for the position of the 72.5 decimal point in the quotient. 65.1_ Check: .93x3.78 = 3.5154. 7.44 7.44 In practice, the decimal point in 72.5, etc., would be omitted. In the division of decimals: Multiply both dividend and divisor by such a number (10, 100, etc.) as will make the divisor an integer. Then divide, giving the quotient the same number of decimal places as are possessed by the dividend as changed. 94 DECIMAL FRACTIONS 5. The following is a record of the number of pounds of milk given at the Dairy Barn by two cows, Black Beauty and Hulda, for the year 1910. BLACK BEAUTY HULDA January 254.9 ft> 311.4 ft> February 812 318.4 March 740.5 366 April 679.5 305 May 664.5 303.8 June 756.8 186.5 July 634.3 658.2 August 689 767.4 September" 483 656 October 458 514 November 379 479 December 351.1 377.2 Reckoning 8.6 pounds of milk to the gallon, find how many more gallons were given by Black Beauty than by Hulda. Find the average number of gallons per day given by each cow during the year. 6. The Institute bought 500 sacks of corn, weighing in all 56,224 pounds at $.67 per bushel. The firm alj lowed a reduction for freight amounting to $.20 per cwt. Find the net cost of this shipment of corn. 7. The Washburn Crosby Milling Co., Louisville, Kv., sold the Institute 200 sacks of flour, 24 pounds to the sack, at $5.3U per barrel. The amount paid by the Institute for this flour was $132.50. How many pounds were reckoned to the barrel according to this bill? (Orj dinarily 196 pounds of flour are regarded as> 1 barrel.) DIVISION 95 8. The Institute bought 1 car of hay, weighing 22,680 pounds, at $15. 25 per ton. A reduction of $22.45 for freight was allowed on the shipment. What did this hay cost the Institute? Di vi de as indicated. 9. 1.0368-8.64 14. 536.09-.0038 10. 1782.5-3.875 15. 41.7362-3 006 11. 372.897-.0378 16. 57.649-100.07 12. 47.638-98.63 17. .0006-.034 13. 506.81-976.345 18. 54.3-86.475 19. Divide (a) 18.6 by 10. (b) 3.87 by 10. (c) 56.87 by 100. (d) 373.9 by 100. (e) 1756.7 by 1000. (f) 3.72 by 1000. 20 How is the position of the decimal point affected when a number is divided bv 10? By 100? By 1000? 21. The Institute bought of Winter LoeD Co., of Montgmery, Ala., 10 barrels of granulated sugar, weigh¬ ing in all 3573 pounds, at $4.90 per cwt. Find the amount paid for this sugar. 22. Find the amount paid by the Institute for 4190 pounds of hay at $.72/4 per cwt. 23. For printing the Institute catalogue of the year 1910-1911, 46 reams of "'hite book paper were purchased. This paper cost $5.60 per cwt. Each ream weighed 60 pounds. The paper and packing weighed 3^03 lb., on which the Institute paid freight at the rate of $1,055 per cwt. The cost of hauling this paper from the depot to the Printing Office was $1.00. Find the total cost of this paper. 96 DECIMAL FRACTIONS 14. For covering the catalogue of the year mentioned, 1500 sheets of cover paper were purchased at a cost of $4.00 per 100 sheets. The Daper was shipped in a package weighing 300 pounds. Freight charges paid by the Institute were at the rate of $.93 per cwt. The hauling of this paper from the depot cost $.25. Find the total cost of this cover paper. 15. The feed used at the Dairy Barn for one month was as follows: 98,965 pounds cotton seed hulls («; $ .47 per cwt.; 128,732 pounds of rape (?; $ .25 per cwt.; 20,400 pounds of cotton seed meal (£<> $1.35 per cwt.; 10,800 pounds of shorts @ $1.50 per cwt.; 900 pounds of corn meal («; $2.00 per cwt.; 600 pounds of bran (horts; 1/2 pounds of bran; 50 pounds of rape. Compare the value of the milk given by this cow during the week with the cost of the feed consumed by her during the same time. 29. The record of Agnes, an average No. 3 cow, dur¬ ing the same week was as follows: MORNING AFTERNOON March 5. 5 pounds 4 pounds 6. 5 6 7. 4 4 8. 4 4.2 9. 4 4 10. 4.2 3.6 11. 4 4 For each day of the week, the feed of all No. 3 cows was as follows: 30 pounds of cotton seed hulls; l.'i? pounds of cotton seed meal; 1*2 pounds of shorts; l2 pound of bran; 50 pounds of rape. Compare the value of the milk produced with the cost of the feed of this cow for the week. DIVISION 99 30. The Institute bought of the Loeb Hardware Co. of Montgomery, Ala. the following: 1 keg of No. 2 front horse shoes, $4.25; 1 keg of No. 3 hind horse shoes, $4.25; 1 keg of No. 4 hind horse shoes, $4.25; 6 bars of IP' round iron, 88 pounds, at $2.45 per cwt.; 6 bars of round iron, 50 pounds, at $2.55 per cwt., 6 bars i" round iron, 30 pounds, at $2.75 per cwt., 6 bars of W" round iron, 20 pounds, at $2.95 per cwt. Find the cost of this order. 31. Schloss & Kahn of Montgomery sold the Institute .17 sacks of fertilizing salts, weighing in all 2610 pounds, at $5 per ton. Find the amount paid for the salts. 32. In the office of the Institute Business Agent, the method used in estimating the value of a load of coal at a given price per ton is as follows: Suppose that it is requir¬ ed to find the value of a load of coal weighing 1725 at $4 per ton. (1) Point off three decimal places in 1725, get¬ ting 1.725. (2) Divide $4 by 2. $4-^2 = $2. (3) Find the product of 1.725 and $2. 1.725X$2 = $3,550. This product, $3.55, gives the value of 1725 pounds of coal at $4 per ton. Explain how this procedure gives the desired result. 33 The I nstitute purchased from the Bessemer Coal, Iron and Land Co. of Bessemer, Ala. 2 cars of coal. One car contained 81,000 pounds of coal and the other car contained 59,400 pounds of coal. This coal sold at $1.40 per ton. The freight on the shipment was at the rate of $1.80 per ton. Find total cost of the two cars of coal. 100 DECIMAL FRACTIONS 34. The Roden Coal Co. of Marvel, Ala. sold the Institute one car of coal containing 80,500 pounds at $2.85 per ton. The freight on this coal was at the rate of $1.61 per'ton. Find total cost of the coal. 35. On one day 64 head of cattle, weighing altogether 36,745 pounds, were purchased by the Institute, the price being $2.75 per cwt. Find the cost of the cattle. 36. On another day 13 head of cattle, weighing 6305 pounds, were purchased at the rate of $2.80 per cwt. Find the amount paid for the cattle. BUSINESS FORMS Exercise 43 The tin cans used at the Canning Factory in 1911 were purchased from the American Can Company. On pages 102, 103, 104, and 105 are reproduced (1) the order given by the Business Agent of the Institute, (2) the reply of the firm, (3) the bill for the goods, and (4) the freight bill. 1. The students will make a careful study of the corre¬ spondence and the bills. 2. Verify the "extensions" on the bill of the goods, that is, see if the figures given under "amount" are correct. 3. Find out what is meant by the statements and signa¬ tures within the enclosed space on the hill: "Extensions O. K. C. N. P.," etc. 4. Verify the freight bill. 5. Secure from your trade instructor (1) the kind and quantity of materials used in connection with some work of the division, (2) the name of the firm handling these materials, and (3) the prices charged by this firm for the same. With this information, bring into class a letter written to the firm ordering the materials designated. 6. Make out a bill in proper form for the same. 7. Secure (through teacher) and study carefully actual bills of goods purchased by the Institute. Verify the extensions in each case. 8. On the regular forms provided for that purpose, make out a bill for some goods sold by your industrial division or for some services performed by the same. 9. The class will visit the Institute Commissary and observe the business forms used in the ordinary transac¬ tion of its business. BUSINESS FORMS BOOKER T. WASHINGTON WARRENLCGAN Principal treasurer The Tusxegee Normal and Industrial Institute FOR THE TRAINING OF COLORED YOUNG MEN AND WOMEN Tuskegee Institute, Alabama ERNEST T. ATTWELL BUSINESS AGENT March 27, 1911. Tne American Can Company, Soutn Atlantic District, AtlanLa, Ga. Gent1emen: As per quotation left with the writer "by your Mr. F. W. Uatnright, pl-ase ship us the following: 15.000 #10 Cans, with solder hemmed caps, with 2- 7/16" opening. 10,000 #3 Cans, with solder hemmed caps, wi th 2= 7/16" opening. 5,000 #1 cans, with solder hemmed caps,with 2- 7/16" opening . We figure that the above will make upa carload shipment. However, if it does not, we would be pleased to have you reduce the number or add thereto in the same proportion as above, in order to make up a carload. Kindly advise us in the matter by re turn mai 1. Very respe c tf u 1 ly yours, E. T. Attwell Business Agent. BUSINESS FORMS 103 AmehicaiN Cain Company South Atlantic District Marietta St. and Jones Ave. e. k. philip manager Atlanta, Ga. Apr i 1 6, 1911. Mr. E. T Attwe11, Business Agt., Tuskegee N. & L Institute, Tuskegee Institute, Ala. Dear Sir: We duly receivea your valued order of the 27th ult. for a oar load of #2, 3 and 10 Standard Packers' Cans, with 2- 7/16" opening and Solder Hemmed Gaps, to be shipped assorted in oar from our Baltimore Factory. This specification will more than fill a 36-ft,, car and will come pretty near f11 ling a 40-f t. car. As we under¬ stand it, however, you desire us to cut, the specification down on each of the sizes m "the same proportion as or¬ dered, so as to makeup a36-ft. car¬ load and we are notifying our factory accord ingly. Thanking you for the order, which we assure you will be shi ppea prompt 1 y andfollowed with tracer, we are, F. L. Yours truly, E. R. Philip Manager. s 0i o American Can Company Maryland Trust Building Baltimore April 10, 1911. Sold to Titskegee N2 cup of milk, 1% teaspoonfuls of baking powder, 1 >2 cups of flour, 1 teaspoonful of spice, 1 teaspoonful of vanilla flavoring. Find the Cost of the materials for this cake at current Commissary prices. Se¬ cure from Cooking Division all necessary information cot.' cerning the weight of 1 cup of butter, etc. REVIEW 6. The following is a recipe for chocolate custard: cup of milk,yk cup of sugar, 1 egg, 2 ounces of chocolate, % teaspoonful of vanilla, 1 speck of salt, cinnamon to taste. Find the cost of the materials for this custard at current prices. 7. A recipe for cottage pudding follows: 2 tablespoon- fuls of butter, ^/z cup of sugar, 1 egg, 3A cup of milk, 2 teaspoonfuls of baking powder, \ l/2 cups of flour, K tea- spoonful of salt. Find the cost of these materials at cur¬ rent prices. 8. The Institute purchased for the Dressmaking Di¬ vision 366/4 yards of lawn at $.12 :/2 per yard. What was the value of this lot of materia]? 9. The Easter waist worn by each of the Senior girls in 1909 required 3 yards of material costing $.11 *-2 per vard. The thread used was estimated at $.02/4; the buttons, at $.09. The Dressmaking Division charged $.20 for the making of each waist. This waist sold for $.70. Find the gain on each waist. 10. The material used in making a hat in the Mil¬ linery Division was as follows: l1^ vards of bobbinet at $1.37>2 per yard; 4 yards of lace at $.45 per yard; 18 inches of silk at $.62 ^ per yard; 2 yards of straw at $4.00 per dozen vards; 9 roses at $5.00 per dozen; 1 plume, $6.00; 1 wire shape, $3.50; 1 spool of linen thread at $1.50 per dozen spools. Find the cost of the material used in the making of this hat. 11. The Institute bought from the Alabama Machinery and Supply Co. of Montgomery, 437 12 feet of -U-inch pipe at $4.60 per hundred feet. Find the value of this pipe. REVIEW 109 12. An individual sold the Institute a cow weighing 535 pounds at $2.12^ per cwt. Find the amount paid for this animal. 13. One wall gi White Memorial Hall is 64',Iong, 37' high, and 18" thick. " In this wall there are 18 win¬ dows, each 3'XS'. At the time of the construction of this wall, the Brickmasonry Division estimated the cost of laying 1000 bricks as follows: labor, $4.00; 1 bar¬ rel of lime, $1.25; Y-z cu. yd. of sand, $.40; 10 pounds of mortar stain, $.23; bricks, $7.90 per M.. Al¬ lowing 22 bricks to the cubic foot, find the cost of con¬ structing the wall. 14. In constructing a pit at the Institute Greenhouse, a brick wall 107' long, 2' high, and 8/; thick was built. Using the information given in the preceding problem, find the cost of constructing this wall. 15. In installing a boiler for heating purposes, the Brickmasonry Division built a four-walled brick founda¬ tion 17' long, 9' 6" wide, and 2' deep. The walls were 24" thick. Find the cost of the brick used in this foun¬ dation at $7.90 per M. 16. On Jan. 5, 1911, Schloss & Kahn of Mont¬ gomery, Ala., sold the Institute the following: 3 sacks of navy beans, 480 pounds, at $2.75 per bushel: 1 barrel of grits $4 00; 2 sacks of rice, 200 pounds, at $.05/4 per pound; 3 cases of macaroni at $1.90 per case; 5 cases of lump starch, 250 pounds, at $.03^2 per pound; 5 sacks of salt at $.50 per sack; 2 cases of Royal Baking Powder, 4 dozen cans, at 12.50 per dozen. Make out the bill in proper form. practical applications in the Tinsmithing, Painting, Carpentry, and othef divisions of the Institute* it is often necessary in estimat¬ ing the material required in certain operations, to compute the areas of figures which are not rectangles. For in¬ stance, in calculating the quantity of tin required to covet a roof, etc., the area qf figures other than rectangles must frequently be found. We shall now1 consider some of the figures commonly met with in such Calculations. Triangle? Parallelogram T rape^oid A triangle is a figure bounded by three straight lines. A parallelbgrarrt is a four-sided figure (quadrilateral) In which the opposite sides are parallel, that is, they' never meet however far they are produced< AREAS 111 A trapezoid is a four-sided figure in which two sides are parallel. A straight line is perpendicular to another straight line when it makes a right angle with it. The base of a figure is the side upon which it is sup¬ posed to stand. The altitude or height of a figure is the perpendicular distance to the base from the vertex or side opposite the base. A D In the parallelogram ABCD, DC is the base and AE is the altitude. The triangle ADE is equal to the triangle BCF. Then, the parallelogram ABCD is equivalent to the rectangle ABFE. The area of the parallelogram is equal to the area of a rectangle having the same base and altitude. The area of a rectangle equals the product of the base and altitude. The area of a parallelogram is given by the product of the 112 PRACTICAL APPLICATIONS two numbers which express its base and altitude m the same unit. F B In the figure, the triangle ABC is Yi of the parallelo¬ gram ABEC which has the same base and altitude. 1 hen, the area of the triangle is of the area of a par¬ allelogram having the same base and altitude. Th e area of a triangle is given by y? the product of the num¬ bers which express its base and altitude in the same unit. B C The trapezoid ABCD is divided by the line BD (called a diagonal) into two triangles, ABD and BCD. These two triangles have the same altitude BE. The area of the trapezoid is equal to the sum of the areas of these two AREAS 113 triangles. Thus if BC = 3 ft., AD=10 ft., and BE = 4 ft., the area of the trapezoid is equal to /zXl0x4xl sq. ft. + >2 X3X-±X 1 sq. ft. = !-_> (10 + 3) X4 X 1 sq. ft. = 26 sq. ft. Th e area of a trapezoid is found by taking half the sum of its two bases (expressed in a given unit) and multiplying the result by the altitude (expressed in the same unit). Exercise 45 1. The lower part of a partition in the Repair Shop is a rectangle measuring' 12/x24/. The upper part is a triangle with a base of 24' and an altitude of 1CK. On one day this partition was painted. The paint used cost $1.75 per gallon. The man who did the work received $1.96 per day. Find the total Cost of the job, if a gallon of paint will cover 500 square feet of this kind of work, and a man Can cover 800 square feet of the same in 1 day. 2. The tin roof of Tompkins Hall was laid by the Tinsmithing Division. According to the manner in which the tin was laid, 28 pieces of tin (20//X28//) were required to cover 1 square (100 sq. ft.). This tin cost $15.10 per box of 112 sheets. In Covering each square, there were also used 5 pounds of solder, costing $.22/4 per pound, and sheathing paper costing $.25. The labor cost $1.50 per square. The class will actually measure roof and estimate the cost of covering the roof. 3. Deducting I" from the length and from the width of each sheet for fastening, show that the number of sheets allowed for each square in the preceding problem is correct. 114 PRACTICAL APPLICA TIONS 4. Find the cost of painting this roof at current prices. 5. Observe the shape of the ceiling in the kitchen of Tompkins Hall. Give a sketch of it. For convenience in calculation, the ceiling may be divided into the following figures: 1 rectangle, 42/x86/; 2 rectangles, 2'x9)4'; 2 rectangles, 11)4'X14/^'; 1 rectangle, 15 7-2'X 15^?'; 2 triangles, base, 14/^', altitude, 3/2'; 2 triangles, base, 9)4', altitude, 9)4'. Exercise 46 1. The plans for a dwelling erected in Greenwood in 1911 were made in the Architectural Drawing Division. Th is dwelling contained the rooms as given below: SIZE OF ROOM Kitchen 12'X14'X11' Library 131'x 161'X11' Parlor 13^x16^x11' Bed Room 12'x 14'X10' Bed Room 14'xl6'6"xl0' Bed Room 13'6"xl4'6"xl0' Bed Room 13'6"xl5'6"xlO Bath Room 6'6'/X7'6'/X10' Study 7'3"xl0'6"xl0' Hall 10'X 22'x 11' Hall 10'x 18'x 10' AREAS 115 The dining room of this house is 11' high and contains a bay window. For convenience, the floor of the dining room may be considered as composed of 1 rectangle 14/4' X 15>2", and 1 trapezoid, whose altitude is 3' and whose two bases are respectively 12'G" and 4'IQ". The walls of the dining room are: 14^2'Xll', 15}4'Xll/(2 walls), 1'Xll' (2 walls), 4/10//Xll/ (3 walls). Find the cost of the plastering done on this entire house, making no deductions for openings. Add 30 square feet for closets in the second bed room. 2. Find the cost of painting the floors of the dining room and the study at local prices for such work. 3. Find the cost of covering the floors of the bath room and kitchen with linoleum. Secure (through teacher) the necessary information concerning the widths and prices of linoleum in local stores. Give drawings showing how you would lay the linoleum. 4. Find the cost of covering the floors of the four bed rooms with matting at local prices. Give drawings to show how you would lay the matting. Two closets at one end of the second bed room give a space 18//X48//. 5. Find the cost of covering the floors of the library and parlor with carpet at local prices. Give drawings 6. Suggest some way of treating the floors of the two 'halls and estimate the cost of the same at local prices. 116 PRACTICAL APPLICATIONS N7. The roof of the house: under consideration was covered with shingles. This roof consisted of the follow¬ ing figures: From the above are to be deducted for dormer windows 1 triangle with a base of 12' and altitude of ll'; 2 trian¬ gles, each with a base of T and an altitude of 1%'\ 2 rectangles Allowing 1000 shingles to the square (100 sq. ft.), find the quantity of shingles necessary to cover the roof of this house. Find the cost of these shingles at current prices. In the Blacksmith Shop iron tires are put on the wheels of the vehicles built in the Institute Shops. In estimating the amount of iron required for the tire of a wheel, it is' necessary to find the circumference of a circle. A circle is a plane figure bounded by a curved line every point of which is at a given distance from a point within, called the center. 2 triangles, base 33', altitude 23^; 2 trapezoids, bases 40' and 7', altitude 23'; 4 trapezoids, bases 12' and 7', altitude 7'; 2 trapezoids, bases 10%' and 2', altitude 10/^'. THE CIRCLE The bounding line of a circle is called the circum¬ ference. The diameter o f a circle- is a straight line drawn through the center and terminating in the circumference. A radius of a circle is a straight line drawn from the center to the circumference. THE CIRCLE 117 The circumference of a circle is found by multiplying the diameter by 37". In the Machine Shop, where threat accuracy is often necessary 3.1416, instead of 3-1-, is used in finJing the circumference of a circle. The area of a circle is equal to the square of the radius multiplied by 3y. The "square" of a number is equal to the product obtained by taking the number twice as a factor. Thus, the square of 3 = 3X3 = 9. The area of a circle whose radius is 2" is 2X2X—7?-Xl sq- in., or 12sq. in. Exercise 47 1. The diameter of the front wheels of a wagon made in the Institute Shops was 42//. The diameter of the rear wheels was 48/;. The iron of which the tires for these wheels was made was \l/\" wide and thick. For welding each tire a length equal to the thickness of the iron is allowed. The weight of 1 lineal foot of the iron mentioned is 1.56 pounds. Find the cost of the iron used in making the four tires, the price of the iron be- ng $2.30 per cwt. and the freight on the same being $.224 per cwt. 2. At the Blacksmith Shop three circular bands were made for a vessel in which fruits are scalded at the Canning Factory. The material of which these bands were con¬ structed was 1%" wide and /i" thick. The diameter of each band was 32^//. Allowing %" for welding each band, how long a bar of iron was required to make the three bands? This iron weighs 1.04 pounds per lineal foot and cost $2.55 per cwt. (including freight). Find the cost of the iron used in the construction of the three bands. 3. The bottom rim of the vessel mentioned was made of the same material. Unlike the three bands, this rim lies "flat." The outside diameter of the rim was 31 Vz". In estimating the length of iron for this rim, the diameter to be taken was measured from center of stock to center of stock. Allowing l/\'' for welding, find the cost of the material in this rim. 118 PRACTICAL APPLICATIONS 4. The two wheels of one of the Institute dump carts have a diameter of 5' and are fitted with tires 2,'j " wide and V?" thick. This iron weighs 4.17 pounds per lineal foot and costs $2.86 per cwt. Allowing y?" for welding, find the cost of the material in the tires of the two wheels. 5. A measuring wheel used at the Blacksmith Shop makes 24;/ to the revolution. What is the diameter of this wheel? Find on a scale the length of this diameter to the nearest eighth of an inch. 6. At the Machine Shop ten slots were cut in the rim of a circular disc 3" in diameter. Each slot was tV' wide. These slots were equally spaced on the rim. Find the distance on the circumference of disc between any two successive slots. 7. Find the area of the face of a disc which is 8" in diameter. 8. The pressure of steam against a piston 12// in diameter is 85 pounds to the square inch. Find the total pressure upon the piston. LUMBER MEASURE The wood work on a one-horse farm wagon was done in the Wheelwright Shop. Before we can compute the cost of the materials used in the construction of this wag¬ on, it will be necessary to find the number of board feet in the lumber used, for the Institute buys its lumber at given prices per 1000 board feet. A board 1 foot long, 1 foot wide,- and 1 inch thick contains 1 board foot of lumber. (See board foot exhibit¬ ed by teacher.) The number of board feet in a piece of lumber is equal to the product of the numbers which express its length in feet, its' width in feet, and its thickness in inches. A thickness less than' 1 inch is to be reckoned as 1 inch. Persons who deal in lumber usually use the word "foot" instead of "board toot". LUMBER MEASURE 119 1 he coupling pole of the one-horse farm wagon requir¬ ed a piece of lumber measuring 2" X3 U " X 12'. Then, in this piece of lumber there were 2 X 3 '4 X J* bd. ft. ==6^2 bd. ft, 11 Hxercise 48 1. The farm wagon mentioned above required in its con¬ struction the following pieces of lumber: FRONT GEARING No. of pieces Measurements Kind of wood 2 1-^"x4^"x9' Oak 1 2^"x3"x53" Oak 1 2i.;"x2i,"x2(r Oak 1 3" X 3/4" X 41" Oak 1 2^"x2"x51" Oak 2 i;4"xiM"x33" Oak 1 1M"x2>2"x46" Oak 1 l->i"x2"x46" Oak 2 l"x3"x 12" Oak REAR GEARING 1 2^"x3"x53" Oak 1 2 >2"'x 3 >2" x 49" Oak 2 2"x3V2"x42" Oak 2 I"x3"xl2" Oak COUPLING POLE 1 2"x3/4"xl2' Oak BODY 2 1^"x3>4"x12' Oak 1 1-%"x4"x50" Oak 1 1-H"x2j4"x50" Oak 1 IH"X2>A"X12" Oak 3 I"xl2"xl2' Oak 2 1"X12"X40" Poplar 2 l"x 12' X12' Oak 14 I"x2"xl2" Oak 120 PRACTICAL APPLICATIONS 1 he spokes for the wheels cost $3.25; the hubs, $1.10; the rims, $1.75. The labor in the Wheelwright Sho,p cost $4.02. The iron work, including labor, in the Black¬ smith Shop cost $18.00. The painting of the wagon cost $4 00. The oak used cost $23 per M; the poplar, $65 per M. Find the total cost of producing this wagon. 2. Class will visit Institute Sawmill and LumbtrYard. PERCENTA G'E Exercise 49 1. The Montgomery Fruit and Produce Co sold in Montgomery for the Institute 39 crates of peaches at $1.75 per crate and charged as commission -10% (read 10 per cent) of the total amount received for the peaches. Expressage on this fruit cost the Institute $6.82. Find the net amount received by the Institute for this fruit. Per cent means by the hundred. Then, 10% means tW, or .10. 5% means Too, or .05. Commission is the amount charged by an agent or fiim for buying or selling for another. The solution of the preceding problem follows. 39X$l-75-—$68.25, amount received for 39 crates of peaches at $1.75 per crate. 10% of $68.25—. 10 X $68.25-—$6,825 Then, the commission charged by the firm was $6.83 $8.56, expressage 6.83, commission $15.39, total charges on transaction. $68'25 $15.39-~=$52.86, net amount received by the Institute. 2. McCollough Bros, of Atlanta, Ga. received from the Institute 42 crates of peaches. 1 he firm sold 21 crates at $2.25 each and 18 crates at $2.00 each. 4 crates were lost in repacking. Expressage on the shipment was $18.48. The firm charged 10% commission. Find net amnunt rerpived bv the Institute. 122 PERCENTAGE 3. M. P. Wilcox of Montgomery received 5 crates of peaches from the Institute which were sold at $2.25 a crate. Find the net amount received by the Institute, after paying 10% commission and deducting $1.10 for ex- pressage. 4. J. J. Payne of Atlanta received 36 crates of peaches from the Institute which were sold at $2.50 a crate. Expressage on the shipment was $16.28; the commission charged was 10%. The agent returned to the Institute 44 empty crates for which he received $.10 each. How much did the agent remit to the Institute? Exercise 50 Express the following as common fractions in lowest terms: 1. 12% 7. 18% 13. CO 2. 25% 8. 15% 14. 62 >v 3. 75% 9. 45% 15. 33 H 4. 60% 10. 110% 16. 66^' 5. 80% 11. 200% 17. 16-'.;' 6. 6% 12. 12/2% 18. w Express as decimals. 19. 3.5% 3-5% = 3 . S — 10 0 035 20. 5.8% 22. 0.8% 24. .75% 21. 3.7% 23. 0.05% 25. y^/o Express as per cents. 26. .325 .325 — 3 2 S 10 0 0 — 3 2 . S — 1 0 0 32.5% 27. .98/ 30. .5 33. .075 28. .101 31. .065 34. •oi x 29. .333 32. .005 35. .575 v/o PERCENTAGE 123 Exercise 51 1. In the cupola at the Foundry, pig iron is melted to¬ gether with scrap iron. For ordinary purposes, such as mak¬ ing window weights, etc., pig iron constitutes 25% of the mixture. What per cent of the mixture is scrap iron? At one time 700 pounds of iron were required for certain castings of the kind just mentioned. How much pig iron and how much scrap iron were used on this occasion? In the above problem, 700, the number of which a certain per cent is to be taken, is called the base. 25%, which states the number of hundreds to be taken, is called the rate. The result of taking a certain per cent of a number is Called the percentage. 2. The amount of coke used in the cupola is 10% of the weight of the iron to be melted. How much coke was used to melt the 700 pounds of iron mentioned in the preceding problem? 3. Machine castings contain 75% pig iron and 25% scrap iron. Iron blocks cast at the Foundry for use in the M achine Shop are 2" square at the ends and 3' long. 1 cu. in. of casting weighs .26 pound. The scrap iron cost $.25 per cwt. and the pig; iron, $16.85 per ton (in¬ cluding freight). Find the cost of the iron required for one of these blocks. 4. The Babbitt metal used in the Machine Shop as a lining for certain parts of machinery consists of 3.7% cop¬ per, 89% tin, and 7.3% antimony. This metal is sold in five-pound bars. Find the number o' pounds of copper, of tin. and of antimonv in each bar. 124 PERCENTAGE 5. On one day 182 pounds of cream were churned at the creamery. A test showed that 32% of this cream was butter fat. Find the number of pounds of butter fat in the cream. 6. The Creamery received from the Dairy Barn on one day, 1736 pounds of milk testing 4.5% butter fat. On the same day neighboring farmers sold the Creamery 73 gallons of milk testing 4% butter fat. Find the total number of pounds of butter fat in the milk received from these two sources. (8.6 pounds of milk make 1 gallon.) 7. A rule used at the Creamery in estimating the number of pounds of butter that can be made from whole milk is as follows: Multiply the number of pounds of butter fat in the milk by 1.17. According to this rule, how many pounds of butter ought to be obtained from 150 gallons of whole milk testing 4.5% of butter fat? (8.6 lb to 1 gallon.) 8. To estimate the number of pounds of butter that can be obtained from cream, proceed as follows: Mul¬ tiply the number of pounds of butter fat in the cream by 1.20. On one day J 50 pounds of cream testing 35% butter fat were churned at the Creamery and 69 pounds of butter were obtained. How does this result compare with that which should have been obtained according to rule? 9. On another day 274 pounds of cream testing 30% butter fat were churned and 97 pounds of butter were obtained. Compare this result with that given by rule. 10. Make similar comparisons of recent results in butter making obtained at the Creamery. PERCENTAGE 125 Study carefully the bill reproduced on page 126. Observe that the price of the "cementico'' is $.09 per pound, and, at that rate, the value of the purchase is $27.00. But a reduction of 45% of $27.00, amounting to $12.15, is given. The price, $.09 per pound, is fixed. Instead of changing this price, the firm gives a reduction of 45% of the same. Such a reduction on the list price of goods is called a trade discount. After the freight has been deducted, we see that the Institute owes the firm $13.35. The terms on which goods are sold name the conditions of payment. Notice that on the bill under consideration, the terms are expressed thus: "60-2-10". This means "60 days net, 2% discount in 10 days, that is, payment of $13.35 is expected within 60 days of date, or a further discount of 2% of $13.35 will be given for payment with¬ in 10 days of date on bill. Th is last discount, which is a reduction for payment within a specified time, is called a time discount. This particular bill was paid by the Institute within 10 days of date of bill. 2% of $13.35 = $.267 The Institute was allowed a further reduction of $.27. Then, the amount actually paid by the Institute for the "cementico" was $13.35 —$.27, or $13.08. United States Gypsum Co. Customer's Order No. Manufacturers of Our Order No. Req. 205 Sold to | Address T erms If. o. b GYPSUM PRODUCTS CHICAGO, ILLINOIS Tuskegee N. & 1. Ins ti-tute, E-77305 Date Shipped 5-12-11. Shipped to Tuskegee N. & I. Ins tit/U te. Tuskegee Inst,. Ala. Station Tuskegee Inst.t Ala. 60-2-10 Via C & E i& W & A Mi 11 CAR INITIAL CAR NUMBER WMAKEALL REMITTANCES IN CHICAGO OR NEW YORK EXCHANGE TOCHICAGO OFFICE, 200 MONROE STREET 3-100# drums white cementico. .09 Less 45% Less frt 500 cwt. Jute bads included in this Invoice vill be purchased at 10 cents each if returned promptly to mill from which shipped in good order, freight paid $27.00 12.15 $14.85 1.50 $13.35 PERCEN I'AGE 127 Exercise 52 1. The I nstitute bought from the American Woolen Co. of New York 2 pieces of dark blue cloth, containing together 81Y? yards, at $1.80 per yard^ and 2 pieces of light blue cloth, containing together 117/4 yards, at $1.22^ per yard. Terms 7% discount 4 months; 8% dis¬ count 2 months; 8/4% discount 30 days; 10% disccunt 10 days. The Institute made payment within 10 days. Find the amount paid. 2. The Crane Co. of Birmingham, Ala. sold the In¬ stitute 603 feet of 2-inch black pipe listed at $.36 per foot. A discount of 74.5% on list price was given. Find the amount paid by the Institute. 3. Bernard Frank and Co. of Montgomery, Ala. sold the Institute 10 bolts of cloth consisting of 338 yards at $.10 per yard. Terms: 2% 10 days; 60 days net. The Institute took advantage of the discount. The pack¬ age of goods weighed 150 pounds on which the In¬ stitute paid freight at the rate of $.307 per cwt. Find total cost of cloth. 4. The Institute bought of the Westinghouse Lamp Co. of Bloomfield, N. J. 100 tungsten lamps at $.70 each, 100 tungsten lamps at $1.10 each, 48 tungsten lamps at $1.45 each, 250 carbon lamps at $.20 each, and 175 carbon lamps ac $.30 tach. The discount on the above was 17/4%. An additional discount of 10% was allowed on the tungsten lamps to cover possible breakage. Find the amount paid by the Institute. 5. The Institute bought of L. Dannen >aum's Sons of Philadelphia, Pa. 60 pieces of braid at $.62/4 each. Terms: 6% 10 days; 5% 30 days. The Institute pa d within 10 days. Find the amount of the payment. 128 PERCENTAGE 6. The Pittsburg Plate Glass Co. ■ lanta, Ga. sold the Institute 15 boxes of window g, he price of which, as listed, was $453.50. Discounts ' % and 10% were given. Find the amount paid the or the glass. In this problem, after the first discount of 90% has been taken, the amount remaining is reduced by a discount of 10%. The last re suit gives the amount paid by the Institute. 7. The Crane Co. of Birmingham, Ala. sold the In¬ stitute the following: 16 /4" tees, 5 pounds, at.$.28 per pound, less 45%—5%; 30 l"X/^"tees, llyi pounds, at $.28 per pound, less 45%—5%; 24 1" tees, 16 pounds at $.28 per pound, less 45%—5%; 228 feet of y?" galvanized pipe at $.08/4 per foot, less 55%; 160 feet of 1" galvanized pipe at $.16/4 per foot, less 61%; 208 feet of 3" black pipe at $.75/^ per foot, less 71%. Find the amount paid the firm. 8. The Institute bought of the Electric Appliance Co. of New Orleans, La. the following: 100 glass in¬ sulators at $50.64 per M; 500 feet of No. 6 weather¬ proof wire, 56 pounds, at $16.60 per cwt.; 500 feet of No. 4 weatherproof wire, 84 pounds, at at $16.60 per cwt; 500 pounds of No. 8 weatherproof wire, 41 pounds, at $16.60 per cwt.; 500 feet of No. 10 weather¬ proof wire, 26 pounds, at $17.60 per cwt; 25 soc¬ kets at $.33 each, less 40%; 125 fuse plugs at $2.75 per 100; 25 dry cells at $.20 each; 3 bells at $.28 each; 4 push buttons at $.06 each; 125 oak side brackets at $17.50 per M; 500 feet of No. 10 rubber covered wire at $29.50 per 1000 feet, less 50%>250 feet of No. 8 rubber covered wire at ,$40.00 per 1000 feet, less 50%; 250 feet %" circular loom at $.06 per foot, less 33*/i%; 250 feet of No. 18 fixture wire at $10.10 per 1000 feet, less 50%; 500 feet of No. 18 lamp cord at $25.30 per 1000 feet, less 50%—10%. PERCENTAGE 129 After the discounts indicated were taken, further dis¬ counts for payment within 10 days were allowed: ^2 of 1% on the weather proof wire; 1% on the rubber covered wire; 2>2% on the sockets; 1% on the lamp cord; 2% on all other goods. Find the amount paid by the Institute to the firm in settlement of this bill. Exercise 53 1. Employees of the Institute who trade with its various departments use largely for this purpose coupon books. One such book is good for $20 in trade, and costs $20, but a rebate of $1 is given the purchaser when the book has been used. What per cent of the cost of the book is the rebate? What is meant by ' rebate"? $20;=cost of coupon book. of cost of coupon book* _z_ = .05 = 5% Then, the rebate is 5% of the cost of the book. Note that in the preceding problem, the base, $20, and the per¬ centage, $1, are given and the rate is to be found. Since the per¬ centage is equal to the product of the rate and base, it is seen that the rate ts found by dividing the base by the percentage. 2. At the Creamery the number of pounds by which the butter exceeds the butter fat contained in the cream from which it is made is called the over run. The attempt is made to keep the weight of the over run always about 20% of the weight of the butter fat in the cream. On one day 210 pounds of cream test¬ ing 30% butter fat were churned and 74 pounds of butter Were obtained. What per cent of the weight of butter fat in the cream was the over run? 130 PERCENTAGE 30% of 210 lb. =63 lb., the weight of the butter fat. 74 lb. 631b. =11 lb., the over run. Since 631b. = weight of butter fat. 1 lb. —of the weight of the butter fat. 11 lb. =-§--3- of the weight of the butter fat. Then the over run was XX of the weight of the butter fat. ix = H^ 63 — .1746 - 1746 = -XXA s xx-a 6 = 17 46c/, ' ' u 10000 — 100 ''w/', Then, the over run was about 17.5% of the weight of the butter fat. 3. From 196 pounds of cream testing 35% butter fat, 84 pounds of butter were obtained. What per cent of the weight of the butter fat was the over run? 4. From 216 pounds of cream testing 38r/r butter fat, 99 pounds of butter were obtained. What per cent of the weight of the butter fat was the over run? 5. At the Poultry Yard in January, 1911, the eggs in the 8 incubators then in use were tested with the follow¬ ing results: Incubator No. of eggs No. of eggs No. of eggs No. of put in. broken in turning Infertil e eggs with dead germs. No. 1. 400 2 71' 1 2. 378 8 24 3 3. 163 1 18 1 4. 215 0 29 5 5. 261 0 88 16 6. 226 3 27 4 7. 89 0 16 6 8. 96 1 31 2 What per cent of the eggs not b roken was infertile? What per cent of the eggs not broken contained dead germs? PERCENTAGE 131 6. The uniform dress of a student made in the Dress- snaking Division costs as follows: yards of cloth at $.12^2 per yard; 1 dozen buttons, $.10; 1 spool of thread 3-05; 2 hooks and eyes, $.01; labor, $.50. This uniform was sold for $2.00 Find the gain per cent. (In reck¬ oning gain per cent or loss percent, the cost is always the base.) 7. A pair of shoes made in the Shoe Shop sold for $5.00. The cost of making the shoes was as follows: trimming, $.30; bottom stock (soles, heels, etc.), $1.25; uppers, 2h sq.ft. of leather at $.35 per sq. ft.; incidentals, $.08; labor, $1.75. Find the per cent of profit (gain) made on this pair of shoes. K. In May, 1911. there were 13.300 peach trees in rhe Institute Orchard of which 5346 were bearing. What per cent of the peach trees was bearing at this time? THE EQUATION It will be found of advantage in solving many problems to know something of the equation. 3+9=2x6 x-\- 7 = 20 A statement, like the above in which two expressions (numbers) are said to be equal is called an equation. In the second equation ^ stands for the number which when added to 7 produces 20. This number we know to be 13. for 134- 7 — 20. The teacher will show by actual balance or scales the truth of the following: 132 THE EQUATION (1) The same number may be added to or subtracted from both sides of the equation without altering the equality. (2) Both sides of an equation may be multiplied or divided by the same number without altering the equality. Find the numbers represented by the letters in the follow¬ ing equations. Exercise 54 *=35—17=18. Check: 18+17=35 2. *-8 = 10 Adding 8 to both sides of the equation, we have *= 10+8 = 18 Check: 18—8 = 10 3. *+21 = 50 4. 9 = 17 5. *-30= 5 6. n- 7.3 = 8.7 7. * + 19.4 = 31.2 8. p+ .03 = 7 9. 3*+17 = 47 (3* means 3 times *) Subtracting 17 from both sides, 3^=47 —17, that is, 3*=30 Dividing both sides by 3, jr=10 Check: 3X10+17=47 10. 4* + 7 = 27 13. 6£+ 8=«25 11. 3y — 5 = 22 14. 17*-.3 = 30.5 12. 5*—23 = 17 15. 5.6m + 3.7 = 40.9 PERCENT AGE 133 Exercise 55 1. In machine castings made at the Foundry, 75% of the mixture is pig iron. Find the weight of a casting containing 45 pounds of pig iron. 75% of wt. of casting = 45 lb. 1% of wt. of casting = of 45 lb. = lb. 100% of wt. of casting = 100 X yf lb. = 60 lb. But 100% of weight of the casting is what we are trying to find. Then, the weight of the casting is 60 pounds. By making use of what we have learned concerning equations, we may solve the problem as follows: Let ;r = no of pounds in wt. of casting Then, .75* = 45. Dividing both sides by .75, x = 45^-.75 = 60 Then, the casting weighed 60 pounds. 2. The Institute paid $58.59 for a bolt (21 yd.) of unfinished worsted, 7% discount being given for payment within 10 days. At what price per yard was this cloth listed? Let * = no. of dollars in the price 21 yd. as listed. .07* = no. of dollars in the discount, x—.07^ = 58.59 the no. of dollars actually paid x — .07*= lx—.07* = ,93x .93* = 58.59 Dividing both sides by .93, x =63 Then, the 21 yd. of cloth, at the list price, would cost $63. $63-^ 21 =$3, list price per yd. of worsted. 3. A casting contained 12/^ pounds of scrap iron. This scrap iron was 25% of the weight of the casting. Find the weight of the casting. 134 PERCENPAGE 4. A man received $9.00 on an investment in t.be Tuskegee Co-operative Building and Loan Association, which was 6% of the money invested. How much had the man invested with the association? 5. How much must one invest in the association in order to be assured of an income of $150? 6. For a pair of half soles sewed on the shoes, the price charged at the Shoe Shop is $1.00. This gives the Shoe Shop a profit nf 17H% on the cost of job. Find the cost of the job. 7. One dozen "jumbo blocks" (sole leather) cost the Institute $6.37, after a discount of 2% had been given. Find the list price of this leather at that time. 8. A commission merchant of Montgomery, Ala. sold 12 crates of peaches for the Institute. After deducting $2.50 for expressage, and 10c/r as commission for selling, the merchant sent the Institute $19.10. At what price per crate did the merchant sell the peaches? 9. All milk received at the Institute Creamery is "run" through the separator, a machine which separates milk into cream and skimmed, milk. The butter fat in the orig¬ inal milk flows out in the cream, the amount of butter fat in the skimmed milk being so small as to be negligible in practical calculations. After the separation, the cream and skimmed milk are recombined to form whole milk or cream containing any desired per cent of butter fat. On one day 10 gallons of milk testing 4.5% were made by mixing together skimmed milk and cream testing 45% of butter fat. Find the number of pounds of skimmed milk and of cream used for this purpose. PERCENTAGE 135 8.6 lb.=wt. of 1 gal. of milk testing 4.5% butter fat. 10> 8.6 lb. = 86 lb. = wt. of 1 gal. of milk testing 4.5% butter fat. 4.5% of 86 lb. =3.87 lb., wt. of the butter fat in the 1 gal. of milk. Since we are to regard the skimmed milk as having no butter fat, we see that the 3.87 lb. of butter fat to be found in the 10 gallons of the mixture must come wholly from the cream testing 45% Then, we are required to find the amount of cream testing 45% butter fat which contains 3.87 pounds of butter fat. Let x = no. of lb. of cream required .45* = 3.87 * =3.87 -.45 = 8.6 Then, 8.6 pounds of cream testing 45%, butter fat were used. 86 lb. -8.6 lb. =77.4 lb., the number of pounds of skimmed milk required. 10. During one summer the Institute shipped daily to the Riverside Dairy of Columbus, Ga. 10 gallons of cream testing 20% butter fat. Cream of this kind weighs 8.4 pounds to the gallon. On one day, the shipped cream was formed by combining cream testing 52% butter fat and skimmed milk. How much of the cream testing 52% butter fat and how much skimmed milk were mixed together to obtain the 10 pounds of cream testing 20%? 11. On another day the 10 pounds of cre^m testing 20% were made by combining cream testing 40% and skimmed milk. How many pounds of cream testing 40% and of the skimmed milk were used? (Give results to the nearest ounce.) 12. On another day cream testing 48.5% butter fat and skimmed milk were used to make the 10 pounds of cream testing 20%'. Find the quantity of cream testing 48.5% butter fat and of skimmed milk used for this purpose. 136 percentage 13. The whole milk sent out from the Creamery tests 4.5% butter fat. At one time 20 gallons of such milk were made by mixing together cream testing 39.5% but¬ ter fat and skimmed milk. Find the quantity of cream and of skimmed milk required. RATIO AND PROPORTION In the compounding of medicines in the Institute Drug Room, in the mixing of fertilizers on the Farm, in the making of belt dressing at the Machine Shop, etc., care is exercised, in the case of any given mixftjre, to maintain certain prescribed relations between the amount of any one ingredient and the whole, and between the amount of any one ingredient and that of any other ingredient. For instance, in 1911, all cows at the Dairy Barn giving more than 20 pounds of milk daily were allowed for the day's feed 30 pounds of cotton seed hulls, 5 pounds of Cotton seed meal, 2 pounds of bran, 3 pounds of shorts> and 50 pounds of rape. Now, the total weight of this feed for the day was 90 pounds. The wt. of the cotton seed hulls = g-g. of the Wt. of the whole feed* " " " " " " mtal = A " V " " " bran = im> ' " " " " shorts = 93o~ " '' ,. „ rape =££"" Also, the weight of the bran was |- of the Weight of the cotton seed ttieal, etc. Whatever the amount of feed mixed at one time, whether a quantity sufficient for 1 COW or for 58 COWS, the relation between the weight of any ingredient and the whole feed, and the relation between the Weight of any one ingredient and the Weight of any Other ingredient were as given above, that is, these relations never changed. Such a relation, like those indicated above, between two numbers of the same kind is called a ratio. 138 RATIO AND PROPORTION The ratio of one number to another number is found by dividing the first number by the second. The ratio of 3 ft.-to 6 ft. =A = JL= c 6 ft. 6 2 The ratio of 12 lb. to 4 lb •— ^ '— = 3 4 lb. Note that the ratio is between rtumbers of the same kind, that is, numbers that refer to the same unit, and that a ratio is always abstract. A ratio may be expressed in two ways. The ratio of 5 to 7 may be written as j or 5:7. In the ratio, 5 -7, the first number, 5, is called the antecedent; the second number, 7, is called the consequent. Exercise 56 Express the following ratios first as common fractions in low- est terms and then as decimals (3 places): 1. 10 : 12 5. 3.5 : 7 9. .03 : 1.6 2. 7 ft. : 14 ft. 6. 2.1 : .35 10. 2 >2 : 8 3. 8 lb. : 22 lb. 7. 56 : 72 11. 3tt : Vh 4. 3 ft. : 48 in. . 8. 36 : 6 12. 5 . 2 6 • 3 Exercise 57 1. Six acres of strawberries belonging to the Institute were fertilized with the following mixture: 3 parts nitrate of soda, 4 parts muriate of potash, and 2 parts acid phosphate. 900 pounds of this mixture were applied to the acre. How many pounds of nitrate of soda, of muri¬ ate of potash, and of acid phosphate were used on the 6 acres? According to the above statement, to every 3 pounds of nitrate of soda, there were used 4 pounds of muriate of potash, and 2 pounds of acid phosphate. 31b. +4 lb.+2 lb.— 9 lb. RATIO AND PROPORTION 139 Then, in every 9 pounds of the mixture, there were 3 pounds of titrate of soda, 4 pounds of muriate of potash, and 2 pounds of acid phosphate. 6X900 lb. =5400 lb., the weight of the mixture for 6 A. 5400 lb.-^9 lb. —600, the no. of tirrile that 9 lb. occurs in 5400 lb. 600X3 lb. = 1800 lb.> the weight of the nitrate of soda used. 600 X4 lb. = 2400 lb., the weight of the muriate of potash used. 600X2 lb. = 1200 lb., the weight of ihe acid phosphate used. 2. A fertilizer used at the Truck Garden consisted of 1 part muriate of potash, 2 parts acid phosphate, and 4 parts cotton seed meal. 25 acres planted in cabbage were fertilized with this mixture,, 500 pounds being used per acre. The muriate of potash cost $45 per ton, the acid phosphate, $14 per ton, and the cotton seed meal, $27 per ton. Find the cost of the fertilizer used on the 25 acres of Cabbage* 3. The same fertilizing mixture was used on 10 acre's ■of onions, 12 acres of Irish potatoes, and 18 acres of corn* 500 pounds were used on each acre. Find the cost of the fertilizer used on each of the crops named. 4. A fertilizer used on the orchard consisted of 1 pound of Cotton seed meal to2lA pounds of muriate of potash. Fin^i the cost of a ton of this fertilizer at the prices given in the preceding problem. 5. A cover Crop used on the Orchard consisted of rye and oats sowed in the ratio 1 : 2. 1/. bushels of th;s mixed seed were useJ on each acre. 30 acres were planted in this seed. Fmd the amount of each seed re¬ quired. 140 RATIO AND PROPORTION 6. Trees in the Orchard were sprayed with the follow¬ ing mixture: 2 pounds of arsenate of lead dissolved in 100 gallons of water and 1 pound of lime sulphate dis¬ solved in 60 gallons of water. At current prices, what would 10 barrels of this mixture cost? (31/^ gal. = 1 bbl.) 7. A liquid preparation used in the summer as a belt dressing at the Machine Shop consists of the following: 4 pounds of bees wax, 5 pounds of pitch, 3 pounds of resin, and 13 pounds of neat's-foot oil. Find the number of pounds of each ingredient in 50 pounds of the dressing. 8. A solid preparation used in the winter as a belt dressing at the Machine Shop consists of the following: 6 pounds of beeswax, 5Y* pounds of pitch, 6Y pounds of resin, and 1 pound of neat's-foot oil. How many pounds of each ingredient are in 50 pounds of the prep¬ aration? A proportion is a statement that two ratios are equal. Th us, 3 : 7 = 9 : 21, is a proportion. Find the value of x in the following: Since this proportion is an equation, we can multiply both sides by 15 without destroying the equality. Exercise 58 1. x _ 3 15" 5 3 x — 9 Check: 2. _x _ 5 27_ 9 4. * 2 .006— 3 3. X s_ 4 5. * : 12 = 9: 22 16 RATIO AND PROPORTION 14i 6. X 7 9. ^ 2 = 8 7. X 5 10. X 13= 7 8. X 6 11. x 3.5 = .07 6.4= .15 : 3.2 * : 6 = 3! : 5i In the proportion, 5 : 7=15 : 21, the first and last terms, 5 and 2l, are called the extremes; the second and third terms, 7 and 15, are called the means. The product of the extremes is 5 X 21, or, 105. The product of the means is 7 X 15, or, 105. From this we see that, in a proportion, the product of the extremes is equal to the product of the means. 12. x : 8 = 9 : 4 The product of the extremes is 4x; the product of the means is 8X9, or 72. 4x-72 x~18 13. 5 = 6: 13 16. * 7 — 21 14. *: 4.2 = 11:.6 17. *_A .33~11 15. *:*=*:* 18. 7! 2 Exercise 59 1. On Jan. 18, 1911, in constructing the concrete floor of the Institute Reservoir, there were used 55 sacks of cement. (.95 cu. ft. to 1 sack.) The mixture used* consisted of sand, gravel, and cement, 5 cu. ft. of cement being used to 27 cu. ft. of sand and 27 cu. ft. of gravel. Hew many cu. ft. of sand and of gravel were used on the day mentioned? The cement cost $.65 per sack; the sand, $.80 per cu. yd; and the gravel, $1.00 per cu. yd. Find the cost of the material used. j 142 RATIO AN0 PKOPOKTION 55 X-95 cu. ft =52.25 cu. ft., the quantity of cement used on fhe given day. Since 27 cu. ft. of sand were mixed with 5 cu. ft, of cement, then, the number of cti. ft. of sand used with 52.25 cu. ft. of cement must hear the same ratio to 27 that 52.25 bears to 5. Then, if x represents the number of cs». ft. of sand used with 52.25 cu. ft- of cement, x _52.25 21 ~ 5 " Multiplying both sides of the equation by 27, we obfafn *= — 5 Then, the?e were 282.15 cu. ft. of sand used with the 52.25 cu, ft. of cement. Also, there were 282.15 cu. ft. of gravel in the mix- lure. Why? 55X$-65 2s$35.75, cost of the cement. 282.15-^27—10.45, no. of cu. yd. in 282.15 cm. ft, 10.45,X$.80— $8.36. cost of the sand. J0.45X$1.00 = $10.45, cost of the gravel. $35.75+$8.36+$10.45= $54.56, total cost of material used if? constructing the concrete $oor of the reservoir on Jan. 18", 1911. 2. In putting the finishing layer of concrete on the floor of the Reservoir, a mixture Consisting of cement and sand in the ratio 1 r 2 was used. On one day 7 sacks of cement were used in connection with this work. Find the cost of the sand and of the cement used on the given day at the prices mentioned in the preceding problem. 3. Cement Mocks used in the construction of Tomp¬ kins Hall were made of 3 parts of sand to 1 part of ce-- ment. Find the cost of the material used in the making of a dozen- blocks each measuring S^X lS 'xlS". RATIO AND PROPORTION 143 4. In a drawing of the Institute Chapel, the height of a 24' window was represented by 4", According to this scale, what length represented the height of the 113r tower? 5. At the Creamery 9 pounds of cream testing 50% butter fat are mixed with 91 pounds of skimmed milk to produce 100 pounds of whole milk testing 4,5% butter fat. How many pounds of skimmed milk must be used with 6 pounds of such cream in order to produce whole milk testing 4.5% butter fat? How many gallons of whole milk would be in the mixture? (8.6 lb. to 1 gal.) 6. At the Machine Shop it is estimated that 1 cu. in, of cast iron weighs .2607 lb., and 1 cu. in. of wrought iron, .2816 lb. A piece of machinery made of wrought iron weighs 36 pounds. What would the same piece weigh if made of cast iron? 7. Patterns used at the Foundry are made of poplar and pine. Find out (through teacher) the ratio of the weight of 1 cu. in. of poplar to 1 cu. in. of cast iron. Secure the same information concerning pine and cast iron. Weigh certain patterns at the Foundry, and on the basis of the information that you have obtained, compute the weight of the casting for each pattern. PRACTICAL APPLICATIONS All plane figures bounded by straight lines, such as triangles, quadrilaterals, etc., are called polygons. A prism is a body whose two ends are equal and parallel polygons and whose sides are parallelo¬ grams. We have already dealt with one kind of prism under the name of rectangular soli d. (Page 73.) Locate prism-shaped structures in the shops and on the Institute grounds. It fs often necessary to find the volume of prisms# as, for instance, in computing the capacity of one of the prism-shaped silos on the Institute Farm, in which feed for stock is kept. It can easily be seen that, if a prism is 1 inch in height, the number of cubic inches in the volume of the prism is equal to the number of square inches in its base. Then, The volume of a prism is given by the product of the numbers which express the altitude and area of the base in corresponding units. If the area of the base is expressed in square inches and the altitude in inches, the base and altitude are said to be expressed in correj sponding units. Other sets of corresponding units are: square foot and foot, etc. PRACTICAL APPLICATIONS 145 A body having a uniform diameter with two circles as its ends is called a cylinder^. Many tanks made in the Tin Shop are cylindrical in shape. Locate other cylinders in the shops and on the Insti¬ tute grounds. As in the case of the prism, it is often necessary to find the volume of a cylinder, as, for example, in estimating the number of gallons held by the Institute reservoir. The volume of a cylinder is given by the product of the numbers which express the altitude and the area of the base in corresponding units. The area of the curved surface of a cylinder is given by the product of the numbers which express the altitude and tht cir¬ cumference of the base in the same unit. This is easily seen from the fact that at the Tin Shop in making a cylinder of the kind that we are considering, the curved surface is cut in the form of a rectangle. The base of the rectangle becomes the circumference of the base of the cylinder and the altitude of the rectangle becomes the altitude of the cylinder. Exercise 60 1. Each of the three gables on Tompkins Hall meas¬ ures 35' at the base and has an altitude of 10'. The brick work of these gables is 13" thick. Find the cost of 146 PRACTICAL APPLICATIONS the bricks required to build these gables at $7.90 per M, allowing 22 bricks to the cubic foot. 2. A tank in which fruits are washed at the Canning Factory is 4/93/~" long, 19 " wide, and 14 1 s" deep. Find the capacity. 3. Sides for the Ames engine used by the Institute are cast at the Foundry. Each such plate is y'%" thick. The face of the plate is a trapezoid with bases 15" and 10/4", and altitude 12". On every plate there are four projec¬ tions each ^"Xl"Xl5's". At one time 12 of these plates were cast. Find the cost of the iron in these 12 plates if the castings were made entirely of scrap iron valued at $.25 per cwt. Allow .26 lb. to the cu. in. 4. One of the Emery dormitories is 109'8" long and 40'2" wide. The height of the walls to the top of the cornice is 29 6". The two gables have an altitude of 18'. The wall of the first story is 18" thick; that of the second story, 12" thick. On the first floor there are 25 win¬ dows each 3/4"x6/2// and 3 doors each 6'X7'. On the second floor are 27 windows and 2 doors of the same size as those on the second floor. There are 6 chimneys each 24//x24//x47/6//. The foundation walls of the building are 18" thick and have an average depth of 3/4'. Find the value of the bricks in this building at $7.90 per M. (Figure the chimneys as solid). 5. A set of reinforced concrete steps on the right of Tompkins Hall consists of 22 steps. Each step is 12/ long, 15" wide (on an average), and 6" thick. At the time of the building of these steps, it was estimated that the labor and material required to cover 1 sq. ft. of sur- PRACTICAL APPLICATIONS 147 face with concrete 6r/ thick cost $.35. In addition to the concrete, there were used 22 steel bands each 12 long. This steel cost $.17 per foot. On either side of the concrete steps there is a brick wall of curved shape. One wall was 16" thick, 23' long, 3 high at one end and 10' high at the other end The second wall was 16" thick, 33' long, 4' high at one end and 15' high at the other end. The estimated cost of building these two walls was $14.50 per 1000 bricks laid. Find the cost of the steps and walls together. 6. A gasoline tank made in the Tin Shop for use in the Painting Division was 26" in diameter and 33" in height. Find the number of gallons held by this tank, allowing 231 cu. in. to the gallon. All measurements are inside measurements unless otherwise specified. 7. The milk urn in the kitchen of Tompkins Hall is 41 >2" deep and 26^" in diameter. Find the capacity of this urn in gallons. 8. The coffee urn in the same place is 30/4 " deep and 29/^" in diameter. How many gallons of coffee will this urn hold? 9. An angle plate used in the Machine Shop was cast in the Foundry. This plate consisted of two flat pieces of iron meeting at a right angle and joined by two quarter-cylinders of iron. One piece measured 1"x9/'2"x 11"; the other piece measured I"x9^2"xl0". The radius of each quarter cylinder was 2-H ; the thickness (height), . This casting consisted of 75% pig iron and 25% scrap iron If the pig iron cost $16.85 per ton and the scrap iron $.25 per cwt., find the value of the iron in one of these plates, allowing .26 lb. to 1 cu. in. 148 PRACTICAL APPLICATIONS 10. Each of the semi-circular arches over certain win¬ dows of Tompkins Hall has an inner radius of 6 and an outer radius of 6'18". These arches are 24" thick. Find the number of bricks in each arch. 11. *1 he engine used in the Foundry was built in the Institute Shops. The cylinder for this engine was cast in the Foundry. The outer diameter of this cylinder is 7/^", the inner diameter, 53/s". The length of the cylin¬ der is 8Y\" - Each of two flanges on this cylinder had an inner diameter of 7^//, and an outer diameter of 11" and was 1 in thickness. Find the weight of the iron in this casting. Find the value of this iron at the prices given in Problem 9. 12. The angle plates used in the roof of Tompkins Hall were cast at the Foundry. Each plate consisted of 4 parts each l"x3"xllH"> and two parts each l/i"x 8%"xllY\" • A hole in one of the latter parts was \Y" in diameter and 1/^^deep. This casting consisted of 25% pig iron and 75% scrap iron. Find the cost of the iron in the 32 plates which were used on the roof. 13. The pumping engine of the Institute water plant has a water cylinder 8}4" in diameter with a 10-inch stroke. How much water is delivered at each stroke? 14. A meter registers the number of strokes made by the piston in the water cylinder. Find out (through teacher) the number of strokes recorded by this meter within a given length of time and calculate the number of gallons pumped during the period. 15. Each of two hot water tanks in White Memorial Hall is 20" in diameter and 5' long. How many gallons of hot water can be held in these tanks? PRACTICAL APPLICATIONS 149 16. Find out (through teacher) the measurements of one of the Institute street sprinklers and compute the number of gallons that it will hold. 17. Find the number of square feet in the surface of the body of this sprinkler. Estimate the cost of painting the same at local prices for this kind of work. 18. Twenty trash cans of galvanized iron were made in the Tin Shop. Each can was 18" in diameter and 30" in height. Two laps on the side of each side of the can required 2". The bottom was cut out of a square 20"X 20". Find the value of the iron in these 20 cans, the weight of 1 sq. ft. of this material being 1.656 pounds and the cost of the iron being $3,886 per cwt (including freight). 19 A tank made of galvanized iron was 10" in di¬ ameter and 20" high. One lap on the side required 1", and 1/4" were added to the height for finishing at top and bottom. The bottom was cut out of a square 12"X 12". This material weighed .9062 pounds per 1911 PLEASE LIST EACH CHECK SEPARATELY CURRENCY Dollars Cents 15 GOLD SILVER . 3 10 CHECKS 12 35 8 TOTAL t 1 38 45 NO 56 July 10, 19 11 Henry Anderson FOR Rent Bal. bro't Ford. Dollars 130 Cents 76 Ami deposited Total.... Amt. this Check Bal. car'd Ford. 12 50 118 26 NO^- TUSKEGEE INSTITUTE. ALA.„ July 101 1911, Savings Department Tuskegee N. & I. Institute TUSKEOEE INSTITUTE. ALABAMA Henry Anderson PAY TO THE ORDER OF T^el-ve o no. i adc $ 12^o John H. Smith KEEPING A BANK ACCOUNT 153 INTEREST Money paid for the use of money is called interest. Exercise 62 1. Find the interest on $750 for 3 years 6 months at 4%. $750, principal .04, rate $30.00, interest on $750 for 1 year at 4(Jq 3*2, no. of years 1M)0 90 00 $105.00, interest on $750 for 3 yrs. 6 mo. at 4% In computing interest, allow 30 days to the month and 360 days to the year, except in cases where exact interest is to be found, in which cases 365 days are counted as 1 year. Find the interest on 2. $500 for 2 yrs. 3 mo. at 4%. 3. $675 for 1 yr. 9 mo. at 5%. 4. $1525 for 3 yrs. 2 mo. at 3%. 5. $3050 for 2 yrs. 5 mo. 10 davs at 4}4%. Find the exact interest on 6. $735 from Sept. 3 to Dec. 5, 1909 at 6%. 7. $900 from Mar. 8 to Aug. 6, 1910 at 4%. 8. $840 from Jan. 16 to Feb. 26, 1911 at 5%. 9. $1075 from Nov. 29, 1910 to Jan. 6, 1911 at 6%. 10. Does the Savings Department of the Institute pay interest on its deposits? 11. Secure (through teacher) information concerning the interest paid by banks of the town of Tuskegee. 12. Look among the advertisements in newspapers and magazines in the Institute Library and note the rate of interest paid on deposits in various banks. Report the same to class. $ 200 On the 8th day of May 1911 Jan. 1911. Tuskegee, Ala.,_ !Uje promise to pay to the order of Savings Department Tuskegee Normal and Industrial Institute the sum of Two-hundred. no dollars 100 Value received, negotiable payable at_ Tuskegee, Ala. And_-a>e-_do hereby waive..oar..claim for the exemption of any real or personal property, salary or wages, which is now or may hereafter be under the Constitution and Laws of this or any other state of the United States, wherein we may be residing at or after the maturity of this note ex¬ empted from levy, sale or condemnation, on execution or other process of any court issued for the collection of the debt evidenced by the foregoing promissory note. And we furthermore agree to pay a reasonable attorney's fee for the collection of this note if not paid at maturity. 3 » rt> O "2 5 3 ST O n 3 3S»- a! Witnesses No. Richard S. Williams Chas. M. Wright Henry Abbott [L. S.] [L. S.] [L. S.] o ore 3 <■< 2 E X a. STUDY OP A BUSINESS ENTERPRISE 1SS Fxercise 63 1. Study carefully the note on opposite page. I ind out the rate of interest charged by the Savings Department on such loans. Secure full information concerning such transactions. 2. On a blank form like the one on the opposite page make out a note for $150, dated March 1, 1910 and due May 1, 1910. 3. Secure (through teacher) information concerning the lending of money by the banks of the town of Tuske- gee. STUDY OF A BUSINESS ENTERPRISE Exercise 64 The class will make a careful study of the Tuskegee Co-operative Building and Loan Association as (1) an enterprise in which money can be invested with a guaran¬ tee of a given income and (2) a source of help in the building of homes. REVIEW Exercise 65 1. Students in cooking classes will report to the arith¬ metic class menus covering breakfast, dinner, and supper. Estimate the cost of the materials required to prepare the above for five persons at current Commissary prices. Ex¬ plain in detail your calculations. 2. Students not in cooking classes will compute the cost of some operation being carried on at present in their industrial divisions, as, for instance, the cost of making a buggy, etc. Give detailed statement. Exercise 66 1. The Institute bought 675 pounds of charcoal at $.08 per bushel. Reckoning 22 pounds to the bushel, find the amount paid for the charcoal. 2. An individual sold the Institute 4 head of cattle, weighing altogether 1925 pounds, at $2.80 per cwt., and one hog, weighing 205 pounds, at $.07 per pound. Find the total amount received by the individual. 3. A wheel made in the Wheelwright Shop had a dia¬ meter of 4'. The diameter of the hub was 6/4"; the REVIEW 157 depth of the rim, lyz". How long were the spokes cut from the outside of the hub to the inside of the rim? (See wheel). 4. The diameter of another wheel made in the same shop was 42". The diameter of the hub of this wheel was 8>4"; the depth of the rim, 1 Y\". How long were the spokes cut from the outside of the hub to the inside of the rim? 5. The diameter of a wheel was 36". The diameter of its hub and depth of its rim were 4^"and 1/i" re¬ spectively. How long were the spokes cut from the outside of the hub to the inside of the rim? 6. The Institute bought of G. A. Miller, Statington, Pa., the slate for 11 blackboards in the Academic Building. The lengths of these boards were, respectively, 27'8", 19'11", 27'10", 19'8", 22'7", 25', 25'3", 25'4", 24T0", 8'8", 11'6". The width of each board was 4'. This slate sold at $.16 per square foot. The freight on this shipment, which weighed 5700 pounds, was at the rate of $1,431 per cwt. Find the total cost of this slate. 7. The tin roof of the building containing the Electric Plant of the Institute consists of the following figures: 1 rectangle 12'x26'; 2 trapezoids, each with bases 12' and 63' and altitude 25'; 2 trapezoids, each with bases 76' and 26' and altitude 25'. Find the cost of painting this roof at current prices. 158 REVIEW 8, The roof of Dorothy Hall consists of the following: Number of Triangles Base Altitude 2 49' 24' 5 28' 19.1' 1 3U.5' 24.5' 1 24.5' 3.5' 2 26.5' 4.8' 2 12' 18.3' 2 16.6' 15.8' 2 1.5' 14.3' 2 6 5' 15.3' 4 50' 25.3' # 26.5' 16.5' 2 27' 40' 2 6.25' 13.4' 2 6.5' 23.9' 2 5' 19' 4 14.5' 19' 2 3.5' 23.2' Number of Parallelograms Base Altitude 2 28' 19.1' 1 30.5' 24.5' 2 40' 5' Number of Trapezoids Bases Altitude 2 37' and 51' 22.8' Find the rlumbef of square feet of surface in the roof, Find the cost of painting this foof at Current prices. 9. J. £>. Ransom and Co. of Nashville, Tenn. sold the Institute the following: 207 feet (B. M.) of poplar at $65 per M; 221 feet (B. M.) of poplar at $75 per M; 580 feet (B. M.) of poplar at $85 per M. The firm allowed a discount of 2°/o for payment within 10 days- Find the amount paid by the Institute. REVIEW 15!) 10. The woodwork of a wheelbarrow made in the In¬ stitute Shops required the following pieces of lumber (oak): 2 pes. 2 >2 " x 2 ?4" X 5' 2 pes. 2" X 2/J4"x 14/; 2 pes. 2" x2'4"xl2" 2 pes. 2>2"X2^4"X50" 1 pc. 1" X 12"x28" 1 pc. 1" X 12" X 24" 2 pes. 1" X 12"X 30" The iron wheel used cost $1.00. The iron work in the Blacksmith Shop cost $1.00. In constructing this wheelbarrow, 1 student of the Wheelwright Division worked 3 days at $.35 per day The oak of which the wheelbarrow was built cost $23.00 per M. Find total cost of producing this wheelbarrow. 11. The Institute purchased from Penick and Ford of New Orleans, La. 2 barrels of molasses, containing 125^ gallons, at $.33 per gallon. A discount of 1 }4% was given for payment within 10 days. According to agree¬ ment the Institute also deducted for freight charges on the shipment. The weight of the two barrels of molasses was 1506 pounds. The freight rate was $.21 per cwt. Find the amount paid the firm by the Institute. 12. The Institute bought of the Westinghouse Lamp Co. of Bloomfield, N. J. 50 tungsten lamps at $.80 each and 50 tungsten lamps at $.70 each. The trade discount on these purchases was 17/4%. An additional discount of 10% to cover possible breakage was allowed. How much did the firm receive for these lamps? 160 REVIEW 13. The Institute purchased for use in the Machine Shop 53 feet of belting at $6.72 per foot. Discounts on this price were 60%—10%—10%. Find the amount paid the firm for this belting. 14. J. J. Payne of Atlanta, Ga. sold for the Institute 7 crates of peaches at $2.25 each and 17 crates at $2.00 each. Expressa^e on the fruit cost the Institute $10.56. The dealer charged the Institute as commission 10% of the value of the sales. Find the net amount received by the Institute for this fruit. 15. The total income of the Institute for year ending May 31, 1910 was $210,309.32. Of this amount $14,457.25 was received from students in the form of en¬ trance fees and tuition fees (including fees received at the Training School ). What per cent of the income of the Institute did the students contribute in this way? 16. For the same year $4,500 was received from the State of Alabama. What per cent of the year's in¬ come came from the State? 17. In the construction of the Senior Practice Cottage, the following framing material was used: SILLS NO. OF PIECES SIZE NO. OF PIECES SIZE SIZE 1 5 4 6"x8"—20' 5 6"x8"—14' 6"x8"—18' 4 6"x6"—14' 6"x8"—16' JOISTS 7 36 20 54 8 8 2"x 10"—10' 5 2"x6"—20' 2"xl0"—16' 11 2"x8"—16' 2"xl0"—14' 5 2"x8"—20' 2" x 6" —16' 5 2"x8"—18' 2" X 6" —14' 5 ' 2"x8"—14' 2"x6" —22' REVIEW Hi] 392 10 12 STUDS 2"x4" —10' PLATE AND SUB-SILL 2"x4"—IT 9 2"x4"—18' 2"x4"—16' 8 POSTS 4"x6"—10' 60 4"x4"—10' 30 8 8 RAFTERS 2"x8"~-24' 26 2"x6"—20' 2"x6"—18' 8 2"x6"-16' 2"x 6"—14' 16 2"x6"—12; In addition to the above, 1971 sq. ft. of sheathing and 2039 sq. ft. of weatherboarding were used. Find the cost of all of this material at $16.50 per M. 18. The floors of the cottage were as follows: kitchen, 12'Xl3'; dining room, 14'Xl7'6"; living room, 14'xl5'; bed room, 14'X15'; bed room, 14'Xl6'; bath room, 6'x 9'; vestibule, 5'x7'; pantry, 5x5'; front porch, 10 x14' and 10'xl6'; rear porch, 12 x15'. Add i of the actual number of sq. ft. to be covered, and estimate the cost of the material used for flooring at $20 per 1000 sq. ft. 19. The walls of the rooms of this cottage were 10 high. Find the cost of plastering all of the rooms of the house at $.35 per sq. yd. (no allowances are made for openings) 20. The cottage mentioned in the preceding problems has two brick chimneys. The lower part of one chimney is of the shape of a triangular prism. The base of the triangle is 6', the altitude, 3*4'. The height of this tri¬ angular prism is 4'. The upper part of this chimney is 162 REVIEW of the shape of a rectangular prism measuring 2 X4 X 16/4'. In the lower part of this chimney there are two openings for fire places, each l'x'-X-1? ■ I'1 the upper part of the chimney there are three openings for flues, each 9" • 8" * 16l2'. Find the cost of the bricks used to build this chimney at $7.90 per M, allowing 22 bricks to the cubic foot. 21. The lower part of the second chimney consists of two parts: (1) a triangular prism and (2) a rectangular prism. The base of the triangle is 3' and the altitude,3/2 ; the height of the triangular prism is 4'. The rectangular prism measures I^'x4'x4'. The upper part of this chimney measures 2' x3'X 16/4In the lower part of this chimney there are two openings for fire places, each 1/Xl^'x2'. In the upper part of the chimney there are two openings for flues, each 8"x8 "X I6/2'. Find the cost of the bricks used in the construction of this chimney. 22. The roof of the cottage consists of the following figures: 2 trapezoids, each with bases 46'9" and 13'6" and altitude 19'; 2 triangles, each with base 33 and altitude 19 6 "; 2 parallelograms, each with base 21' and altitude 4 ; 2 parallelograms, each with base 13'6" and altitude 4 6 "; 1 trapezoid with bases 22'and 10' and altitude 11'6"; 1 trap¬ ezoid with bases 28 6" and 14'6" and altitude 11'6". Find the cost of the shingles, for the roof of the cottage at $4.00 per M, allowing 1000 shingles to the square (100 sq. ft.) 23. Machine rolls cast in the Foundry are I/2" in diameter and 8" in length. Find the weight of such a bar, reckoning .26 lb. to the cu. in. REVIEW lOJ 24„ A man hole cover cast at the P'oundry was 191;''7 in diameter and -;b" in thickness. What was its weight? 25. Find out (through teacher) the dimensions of the milk vats at the Creamery and find the number of gallons of milk held by each. 26. Wh at must be the length of a rod cast at the Foundry whose diameter is to be 2" and whose weight is to be 16 pounds? 27. What must be the height of a tank whose diam¬ eter is to be 24" and whose capacity is to be 20 gallons? 28. On a working drawing of a wagon in the Wheel¬ wright Shop, the length of the wagon, which was 7'6" was represented by 55;-/. On the same scale what represented the width, 3'2"? 29. A spray used on the trees in the Orchard consist¬ ed of 20 pounds of lime, 16 pounds of sulphur, and 10 pounds of salt. Water was added to make 40 gallons. In 1908, 4,500 trees were sprayed with this mixture, 1 /i gallons being applied to each tree. The lime cost $.77,'2 per cwt.; the sulphur, $.03/12 per pound; the salt, /4(' per pound. Find the cost of the spray for the 4,500 trees. 30. The feed for chickens at the Poultry Yard is kept in a bin divided into compartments to hold the vari¬ ous kinds of feeds used. Each compartment is, approxi¬ mately, a prism with a trapezoidal base. The measure¬ ments of the compartments together with the kind of feed in each follow: 164 REVIEW measurements of height ok kinu of fffn trapezoidal base of prism prism Corn and oats chops Rases 2'10"and 3'3" ; altitude 4' 1'9" Prepared chick food " " " .. << 2'3" ;; " " " " " 2'io" " " 2' Shorts Cotton Seed Meal Bran 5'2" " " 3' Find the number of bushels of each kind of feed that the bin can hold, reckoning 2150.42 cu. in. to the bushel. 31. Find the cost at local prices of papering the walls and ceilings of the Practice Cottage mentioned in preceding; problems of this exercise. Secure (through teacher) all necessary information from the House and Sign Painting Division. 32. ()n may 6, 1910, the Institute received 6 months' interest on each of the following investments: 30 shares (of stock) of St. Louis and Southwestern R. R. at V.r. 30 shares (of stock) of St. Louis and Iron Mountain R. 1\. at V'. 25 shares I of stock) of Alabama and Great Southern R. R. at 4 Vr. 15 shares (of stock"1 of Missouri and Pacific R. R. at6%. 10 shares 1 of stock) of Norfolk and Southern R. R. at 5'< . I'hc value of each share was $1000. The Trust Company that made the collections charged a commis¬ sion of Vt of total income. Find the net amount re¬ ceived I'M the Institute from these investments. v;.,.i wji,ir is meant by a share of stock". POWERS AND ROOTS When 5 is taken twice as a factor, what product is obtained ? When 7 is taken twice as a factor, what product is obtained? When 3 is taken three times as a factor, what product is obtained? When a number is taken twice as a factor, the resulting product is called the square or the second power of that number. When a number is taken three times as a factor, the resulting product is called the cube or third power of that number. 16 is the square of 4, since 16=4X4. 8 is the cube of 2, since 8 = 2X2X2. 4x4 can be written 42, and 2x2x2 can be written 23. The small figure, called the exponent, placed above and to the right of a number, indicates the number of times that it is to be taken as a factor. Exercise 67 Find the square of the following: 1. 12 5. .3 2. 15 6. .08 3. 70 7. f 4. I 8. 3.02 9. 576 10. .576 11. 2 2 12. 7.002 166 POWERS AND RCO'i f Find the cube of the following: 13. 11 15. 3.8 17. 5.06 16. I 18. 35 20. 53 21. W 23. (I)3 22. (1.2)® 24. (.009)2 While 36 is called the square! of 6, 6 is called the square root of 36. In the same way, while 27 is called the cube of 3, 3 is called the cube root of 27. The square root of 36 may be indicated by Using the radical sign, v • Thus, 1./36 —6 The cube root of 27 may be indicated as follows:: f 27 -3. Exercise 68 Gi ve the foots indicated. 1. 4. 2. 1/49 5. fW 3. 1/144" 6. ifl25 7. f/iW 8. f/1000 9. V i2]T 10 t/225- 225=3X3X5X5= (3X5) X (3X5) / 225 =3X5=15. 11. l/625 14. I 3969 17. i/73375 12. 1/576 15. if 343 18. i/f POWERS AND ROOTS 167 1 i =1 i ioo =10 i ioooo =100. We see from the foregoing that the square roots of numbers between 1 and 100 lie between 1 and 10, and that the square roots of numbers between 100 and 10,000 lie between 10 and 100, etc. Then, the square root of a number containing one or two figures is a number of one figure; the square root of a number containing three or four figures is a number containing two figures, etc. In the number 2304, the number of figures in the square root may be indicated by separating the number into periods of 2 figures each, beginning at the right as follows: 23 ' 04. If t represents the tens in a number of two figures and u, the units, then the number itself is represented by t + u. The square of this number is represented bv (t + u)2. But, as is shown in algebra, (t + u)"=t"+2tu + u2. In the number, 57, t = 50 and u = 7. t" =50" =2500; 2tu = 2x50x7 = 700. uz=72--49. (t + u)2 = (50 + 7)2 = 2500+700+49 = 3249. That 3249 is really the square of 57 can be verified by finding the square of 57 in the usual way. Exercise 69 Find the square root of the following 1. 5776 Dividing the number into periods of two figures each, beginning at the right, we see that the square root con¬ tains two figures. (a) (b) t f u 57 76 | 70+6- -76 57 76 76 t2 -702 49 00 49 2 140 8 76 146 I 8 76 2t • u 146 I « 7fi (j 2tu + u2---6X146 - 8 76 The greatest square in 5700 is 4900. Then t 70. Subtracting 4900 from 5776, we get as remainder 876. This number, 876, must 168 POWERS AND ROOTS contain 2tu u2. 2t=140. Using 140 as a trial divisor, we di¬ vide 876, obtaining 6 as a trial value for u. 2t 1 u 146. 2tu ; u2 = 6 > 146 = 876. Then, 6 is the value of u required. Therefore, ( 5775 = 76. In practice, the shorter form under (b) is to he used. When the root to he found contains more than 2 figures, the above process is repeated until all the figures of the required root are found. 2. 28.5156 The number of roots in this number which contains a decimal is found by separating it into periods of two figures each, beginning at the decimal point and marking off periods to the left and to the right. 28.51 56 | 5.34 25 103 I 3 51 I 3 09 1064 I 4256 1 4256 3. 1379 5. 14161 7. .092416 4. 2601 6. 4.2849 8. .6984 Extract the square root of the following carrying the opera¬ tion to two decimal places. 9. 2 11. 23.7 13. 19 10. 3173 12. 3.1416 14. 53.02 PRACTICAL APPLICATIONS A triangle containing a right angle is called a right triangle. The side opposite the right angle in a right triangle is called the hypot¬ enuse. Thus, in the figure, AB is the hypotenuse. C B It is shown in geometry that The square on the hypotenuse of a right triangle is equal to the sum of the squares on the other two sides. If in the figure, AC = 4, CB=3 AB2 = 32+42 =9+16 = 25 AB = 1/257 or 5. Exercise 70 1. A hip rafter of the roof of a building was found to be the hypotenuse of a right triangle whose two sides were 15' and 35' respectively. Find the length of the hip rafter. ' 2. Another hip rafter of the same building was found to be the hypotenuse of a right triangle whose two sides were 20' and 48' respectively. Find the length of this hip rafter. 3. The gable end of a cottage is of the form of a tri¬ angle two of whose sides are each 24' and whose base is 30'. Find the number of square feet of surface in this gable. (The altitude of the gable Strikes the 30' base in the center.) 170 PRACTICAL APPLICATIONS 4. What must be the diameter of an iron rod cast at the Foundry which is to weigh 16 pounds and to be 6" long? (.26 lb. to the cu. in.) 5. Ten-pound sash weights for windows are cast at the Foundry in the form of round bars 20// long. What is the diameter of these bars? 6. What must be the diameter of the pattern for a cylindrical rod, which when cast at the Foundry is to weigh 36 pounds and to be 14" long? In making patterns %" is to be allowed to every foot for shrinkage. PYRAMID—CONE—SPHERE The teacher will exhibit models of (1) pyramid, 2) frustum of pyramid, (3) cone, (4) frustum of cone, and (5) sphere. Point out what is meant by slant height and altitude of pyramid, cone, frustum of pyramid and frustum of cone. Students will locate on the Institute grounds and in the Shops structures like the solids just described. The volume of a pyramid or a cone is given by one-third the product of the numbers which express the altitude and area of the base in corresponding units. See page 144. The lateral area of a pyramid or a cone is given hy one- half the product of the numbers which express the slant height and the perimeter of the base in the same unit. The perimeter of the base is the distance around the base. PYRAMID—CONE-SPHERE 171 To find the volume of the frustum of a pyramid or the frustum of a cone, proceed as follows: Find the sum of the bases; add to this sum the square root of the product of the bases; multiply this last result by one-third the altitude. By "bases" is meant the number representing the area of the base. The altitude and bases must be expressed in corresponding units. The lateral area of the frustum of a cone or the frustum of a pyramid is found by taking one-half the sum of the perime¬ ters of the two bases and mulitplying the result by the altitude The volume of a sphere is found by multiplying four-thirds the cube of the radius by Jy. The area of the surface of a sphere is found by multiplying four times the square of the radius by 3\. Exercise 71 1. Secure (through teacher) the necessary information and compute the cost of painting the tower of the Insti¬ tute Chapel. 2. A bucket made in the Tin Shop is 9" high. The diameters of the bottom and top were 8" and ll" re¬ spectively. Find the capacity of the bucket in gallons. 3. The two foundations of the air compressors at the Institute Water Plant are made of brick. Each founda¬ tion is 12' square at the bottom, 8' square at the top, and 10' high. Find the cost of the bricks used in constructing these foundations at $7.90 per M. (22 bricks to the cu. ft.) 172 PRACTICAL APPLICATIONS 4. The brick foundation for a press at the Printing Office has a top 3'X3/4' and bottom S'xS}^', and is 3'>2' high. Find the cost of the bricks used in the con¬ struction of this foundation. 5. Find the cost of the bricks used in building the 12 columns of Tompkins Hall, each column being 40" in diameter at the bottom, 30 ' in diameter at the top, and 30' high. 6. Find out (through teacher) the measurements of the boys' swimming pool and estimate the number of gal¬ lons that it will hold. 7. A piston ring for a dynamo was cast at the Foun¬ dry. This casting was of the form of a frustum of a cone. The diameter at one end was 15^"; the diameter at the other end was 13s 8r/. The height was 5-5 s". The cylin¬ drical hole within the casting was 12Y\" in diameter and 5?s" in height. On this casting there were also 4 pro¬ jections, each measuring /4" Xl/4" X3". Find the weight of the casting. 8. A spherical ball cast at the Foundry was 3iV in diameter. Find its weight. 9. The spherical ends of a pair of dumb bells cast at the Foundry were 3/4" in diameter. The handle of each dumb-bell was 4" long with an average diameter of H". Find the weight of one of these dumb-bells. Exercise 72 1. Compute from actual measurements the capacity of the dipping tank for cattle on the Institute Farm. Find out the composition of the dipping mixture and es¬ timate the quantity of each ingredient required to make enough of the mixture to fill the tank. At current prices what is the cost of the mixture required to fill the tank? PRACTICAL APPLICATIONS 173 2. Compute from actual measurements the capacity of one of the silos on the Institute Farm. At the current price of ensilage, what is the value of the ensilage that it can hold? 3. Find the n umber of gallons held by the Institute Reservoir. 4. Find the number of gallons held by the Institute Water Tank. Exercise 73 1. Class will visit the Tin Shop and compute (1) the quantity of material required to make various articles in the shop and (2) the capacity of various vessels in the shop. 2. Class will visit Foundry and estimate the weight and cost of various castings. Exercise 74 The class will visit the Truck Garden and" find the number of acres in the plots planted in different crops. GENERAL REVIEW Exercise 75 1. The W ashburn-Crosby Co. of Louisville, Ky. sold the Institute 1 car of flour. This car contained 240 twelve-pound sacks, which sold at $4.65 per barrel (196 lb.), and 80 twenty-four-pound sacks which sold at $4.50 per barrel. The Institute was allowed a reduction for freight which amounted to $.22 per cwt. Find the amount paid the firm. 2. The same firm shipped the Institute a car of bran containing 400 sacks, 100 pounds to the sack. The price of this bran was $28.00 per ton. A reduction for freight as in the preceding problem was given. What did the firm receive for the car of bran? 3. A double window made in the Institute Repair Shop required the following lumber: No. of Pieces Size No. of Pieces Size 1 2"x8//—7/8r/ 4 1"X6"—6'8" 1 2"x8"—6' 3 1"X6"~ 7'8" 2 2//x6//—6' 2 1"X6"—6' 4 1//X2//—6' 4 V'xV'—V 1 V'x8f,—6' 2 v'xv—y 1 V/2"X21/2"—7'8" 4 j4"x K "—6' 2 %"XVA"—% Find the cost of this material at $18 per M. 4. Armour and Co. sold the Institute 207 pounds of sides at $9.68 per cwt., 213 pounds of shoulders at $.13 per pound, 300 pounds of lard at $.09/4 per pound, 1 barrel of soap, 317 pounds, at $.07/^ per pound, 25 pounds of bologna sausage at $.07K per pound. Make out this bill in proper form. GENERAL REVIEW 175 5. The Institute bought of the Commercial Electrical Supply Co. of St. Louis, Mo. 35 cross arms at $27 per 100 less 25%, 15 cross arms at $37 per 100 less 25%, and 100 wood pins, $1.60. How much did the firm receive for these supplies? 6. The Loeb Hardware Co. of Montgomery sold the Institute 500 dry spokes at $6.45 per 100 and 100 dry spokes, $5.00. The trade discount on the above was 10%. A further discount of 2% was given for payment within 10 days. Find the amount received by the firm. 7. A water cooler made in the Tin Shop consists of an inner and an outer vessel, each made of galvanized iron. The faces of the outside vessel made the following figures (allowances for seams being included, except where indicated): 4 rectangles, each 12"xl6"; 4 triangles, each with base 12" and altitude 4 triangles, each with base 1" and altitude 1 l/z". 2 seams make a strip 5'X 1/^The outside bottom required a piece 13"xll". The inner vessel has the following faces: 2 rectangles, each 7/4"x20'/; 2 rectangles, each 7"x20;H>"; the bottom of the inner vessel required a piece 8' 'X8". The moulding on the cooler consists of 4 trapezoids, each with bases 13K" and 14" and altitude 3". The top consisted of 1 rectangle 8"x8" and 4 triangles each with base 8/2" and altitude 4 >2". Add for seam a strip /^"x6". I he iron of which this cooler is made weighs .9062 lb. per sq. ft. Find the number of sq. ft. of iron in the cooler. Find the cost of this iron at $4,186 per cwt. (including freight). 176 GENERAL REVIEW 8. The Macon County Oil Co. sold the Institute 31,900 pounds of cotton seed hulls at $11.50 per ton and 515 pounds of linters at $.04 Vs per pound. Find the amount paid to settle bill. 9. The Institute bought of J. F. Rilev of Birming¬ ham, Ala. a car of oats containing 56,640 pounds at $.64s per bushel. A reduction of $162.40 was allowed the In¬ stitute on account of freight charges. Find the amount paid the firm. 10. The following table gives the per cent of protein, carbohydrates, and fats in the feed stuffs used at the Dairy Barn. Protein Carbohydrates F ats Cotton Seed Meal 37.2 16.9 12.2 Cotton Seed Hulls .3 33.1 1.7 Shorts 12.2 50. 3.8 Wheat Bran 12,2 39.2 2.7 Rape 1.5 8.1 .2 At the Dairy Barn an effort is made to maintain in the feed a certain ratio between the protein on the one hand and the carbohydrates and fats on the other. This ratio is called the nutritive ratio. This ratio is computed as follows: (1) Multiply the weight of the fats in the feed by 2.4. (2) Add this product to the weight of the car¬ bohydrates. (3) Find the ratio of the weight of the pro¬ tein to the sum just found. The nutritive ratio, then, may be expressed thus, wt. of protein 2.4X-wt. of fats+ wt. of carbohydrates GENERAL REVIEW 177 If the nutritive ratio is less than 1 : 6, it is called a wide ratio; if it is is greater than 1 : 6, it is called a narrow ratio. At one time the feed for No. 1 cows at the Dairy Barn was as follows: 5 pounds of cotton seed meal, 30 pounds of cotton seed hulls, 3 pounds of shorts, 2 pounds of bran, and 50 pounds of rape. Find the nutritive ratio in this feed. Is it wide or narrow? 11. The daily feed for No. 2 cows was 4 pounds of cotton seed meal, 30 pounds of cotton seed hulls, 2 pounds of shorts, 1/-2 pounds of bran, and 50 pounds of rape. Find the nutritive ratio in this feed. Is it wide or narrow? 12. The daily feed for No. 3 cows was 1% pounds of cotton seed meal, 30 pounds of cotton seed hulls, 1% pounds of shorts, Vz pound of bran, and 50 pounds of rape. Find the nutritive ratio in this feed. Is it wide or narrow? 13. Secure (through teacher) all information neces¬ sary for computing the nutritive ratios in the rations fed at the Horse Barn. 14. The Westinghouse Lamp Co. of Bloomfield, N.J. sold the Institute 48 lamps at $1.35 each and 50 lamps at $1.00 each. A trade discount of 17)4% was allowed on the above. An additional discount of 10% was also allowed to cover possible breakage. Find the amount paid the firm by the Institute. 15. The Institute bought of J. Loeb Grocery Co. of Montgomery, Ala. 300 sacks of 'corn weighing 42,000 pounds, at $.6424 per bushel. Find the value of this corn. 178 GENERAL REV' ;W 16. An engine at the Machine Shop had a piston cylinder 8" in diameter with a 12"stroke. How many cu. in. of steam did it hold? 17. What must be the length of the stroke of a piston in a cylinder whose capacity is to be % greater than that of the cylinder in the preceding problem, and whose di¬ ameter is the same? 18. What must be the diametei of a cylinder the stroke of whose piston is the same as that in the preced¬ ing problem, but whose capacity is 2/2> as great? 19. The Institute bought of Young and Vann Supply Co. of Birmingham, Ala. the following: 21 Yi pounds of packing at $.60 per pound; 24 2" discs at $.18 each; 24 l1/?" discs at $.12 each; 24 1%" discs at $.09 each; 24 1" discs at $.06 each; 24 3/i" discs at $.05 each; 24 discs at $.04 each; 24 2"x2" plain nipples at $.18 each; 24 1^"X1^" plain nipples at $.13 each; 24 l/4"x2}4" plain nipples at $.11 each; 12 }{" air corks at $.45 each; 6 air corks at $.50; 6 72" air corks at $.60 each. Trade discounts were given as follows: 20% on the pack¬ ing and discs, 80%—5% on the nipples; 75% on the air corks. Terms: 2%, ten days. The Institute paid the bill within 10 days. Find the amount sent the firm for these supplies. GF JERAL REVIEW 179 20. Wm. Jessop and Sons of New York sold the In¬ stitute the following: 45^ pounds of cast steel 1}&" square; 48/^ pounds of cast steel l/4"xl"', 2434 pounds of cast steel l/VxH"; 11/4 pounds of cast steel square; 22yi pounds of cast steel 1Y%" square; 2234 pounds of cast steel 5/8" octagonal; 20}4 pounds of cast steel ¥%" octagonal; 10 pounds of cast steel 1%" round; 21 Y\ pounds of cast steel 1" round; 2SY pounds of cast steel round. This steel sold at $.15/4 per pound. In addition to the above, there were sold 10}4 pounds of %" square cast steel at $.17]4 per pound. A discount of 10% was given on the order. Find the amount paid the firm for this steel. 21. H ow long must a 12-pound sash weight for windows be made at the Foundry, if it is desired to make such weights 1/i" in diameter? Reckon .26 lb. to the cu. in. 22. The Institute bought from the Pittsburg Plate Glass Co. of Atlanta, Ga. the following: Size of Glass Price per Box lbox 17"xl7" $28.00 1 box 12"xl5" 26.75 lbox 10"X14" 25.50 1 box 12"xl8" 26.75 lbox 12"x22" 26.75 lbox 12"xl6" 26.75 lbox 10"x 14" 25.50 lbox 10"xl2" 25.50 Discounts on the above were 90%—20%. Terms: 2% ten days. The Institute paid within 10 days of date of bill. Find the amount received by the firm for the glass. 180 GENERAL REVIEW 23. A box of window glass contains as nearly as pos¬ sible 50 sq. ft. of glass. Find the number of lights meas¬ uring 12' 'X 15" in a box. At the prices given above what did each such light cost the Institute? Take account of discounts in your calculation. 24. How many lights 12"xl8" are contained in a box? Find the amount paid by the Institute for each light of this size. 25. Find the amount paid by the Institute for each light measuring 17' 'X 17". 26. A bucket of cylindrical shape made in the Tin Shop was 11" in diameter and 8" high. Find the num¬ ber of gallons that it holds. Express this result correct¬ ly to the nearest Y pt. 27. The link of an iron chain made at the Blacksmith Shop may be considered as being composed of four parts: 2 semi-circular ends and two straight pieces connecting these ends. The chain was made of round iron Y" in diameter. Each of the straight pieces was lY" long. The diameter of each of the semi-circular ends was Y\" (measured from center of stock). Find the length of iron required for one link, allowing Y" for weld¬ ing. One lineal foot of this iron weighs .6612 pound. Find the weight of one link of this chain. At $2.55 per cwt., find the cost of the iron in the chain of 15 links. How long was this chain? 28. The Institute bought from the National Gum and Mica Co. of New York llY ounces of mica at $9.50 per pound less 50%. The firm charged the Institute $.10 for postage. Find the cost of mica. GENERAL REVIEW 181 29. Blocks of iron 3' long and 2" square at the ends are cast at the Foundry for use in the Machine Shop. At the Machine Shop each block is planed down until it is \y% square at the ends. A V-shaped trough is then cut the entire length of the block. This V-shaped trough is 1/4" wide at the top and the point of the V is in the center of the square ends of the block. Find the weight of the block when it is received from the Foundry. Find the weight of the block after the trough has been cut. Reckon .26 lb to the cu. in. 30. Steiner and Lobman sold the Institute 10 bolts of cloth containing, respectively, the following number of yards: 24, 38,48^, 23^, 46^, 41^, 33, 46^, 53^, 42 . This cloth sold at $.22 per yard. 2% was given as discount for cash within 10 days. Find the amount received by the firm. 31. In the report of the Principal of the Institute for the year ending May 31, 1910, the following statement is found: "The value of our plant, including equipment and live stock, is now $1,263,249.90, making an addition of $147,615.09 for the year." Find the per cent of in¬ crease in the value of the plant for the year. 32. The Thread Agency of St. Louis, Mo. sold the In¬ stitute 12 dozen spools of thread at $.58 per dozen less 10%—5%. Find the amount paid the firm. 33. The Institute bought of A. Atzinger and Son of Louisville, Ky. 10 sides of leather, 192 pounds, at $.40^ per pound. Terms: 2%, 30 days. Find the amount paid for leather after the discount had been deducted. 182 GENERAL REVIEW 34. The Cudahy Packing Co. sold the Institute 222 pounds of meat at $.07% per pound. Terms: 10 days. The Institute took advantage of the discount. Find the amount sent the firm for the meat. 35. The Crane Co. of Birmingham, Ala. sold the In¬ stitute 2 valves at $4.00 each less 65%—5% and 3 iron cocks at $5.25 each less 70%—10%—2)4%. Terms: 2%, 30 days. The Institute paid within 30 days of date of bill. Find the amount received by the firm for these supplies. 36. Two end walls were built for a pit at the Institute Greenhouse. Each wall was 6' 3" long, 9" thick, 2' high at one end and 2' 6" high at the other end. Counting 22 bricks to the cubic foot, find the cost of the bricks in this wall at $7.90 per M. 37. A brick cistern near the Institute heating plant has an inside diameter of 12' and is 7/^' deep. Compute the capacity of this cistern in gallons. TABLES TABLES LIQUID MEASURE 4 gills = 1 pint 2 pints = 1 quart 4 quarts — 1 gallon 1 gallon contains 231 cu. in. 31/2 gallons make 1 barrel (in estimating capacity of cisterns, etc.) DRY MEASURE 2 pints = 1 quart 8 quarts = 1 peck 4 pecks = 1 bushel 1 bushel contains 2150.42 cu. in. LINEAR MEASURE 12 inches = 1 foot 3 feet = 1 yard 5/4 yards (16/4 ft.) =1 rod 320 rods(5280 feet) =1 mile SQUARE ]V 144 square inches 9 square feet 30% square yards 160 square rods 640 acres 100 square feet = 1 square foot = 1 square yard = 1 square rod = 1 acre = 1 square mile = 1 square TABLES TABLES CUBIC MEASUR.E 1728 cubic inches =1 cubic feet" 27 cubic feet =1 cubic yarcf 128 cubic feet —1 cord AVOIRDUPOIS WEIGHT 16 ounces — 1 ft). 100 pounds =1 hundred wei 2000 pounds —1 ton MISCELLANEOUS of beans or peas weighs 60ft) oats " 32 ft) corn (shelled) " 56 ft) corn (on ear) " 70ft> White potatoes " 60ft> Sweet potatoes " 50 ft) charcoal " 22ft>