WRITTEN EXERCISE 1. Change 127 to a whole or a mixed number. 1. 81. 4. 141. 7. 800. 10. 193. 13. 5176. 3 2. 90. 5. 225. 8. 3. 140. 6. 150. 9. 9 12 250. 11. 1000. 14. 2336. 75. 12. 2264. 15. 6940. WRITTEN PROBLEMS 1. A ticket seller at a circus took in 641 silver quarters. How many dollars had he? 2. A grocer bought 133 cans of oil each holding of a gallon. How many gallons of oil did he buy? 3. A boy ran 40 times around a track which measured mi. How many miles did he run? 4. A grocer made up 150 packages of pepper each weighing 1 lb. How many pounds of pepper did he use? 5. A baker uses lb. flour in making a loaf of bread. How much flour would he use in making 225 loaves? The Denominator 1. An apple is to be divided equally among some boys. What part will each boy receive, if there are only 2 boys? If there are 3 boys? If there are 4 boys? If there are 5 boys? If there are 6 boys? 2. When the number of boys is increased, is each one's share of the apple increased or diminished in size? 1. How many parts in this oblong? What is each each part called? 2. How many parts in of the oblong? In? In ? In ? If we arrange the answers in a table, we have: 3. Which fraction is the greatest in value? The smallest in value? 4. Which fraction has the largest denominator? 5. Which fraction has the smallest denominator? The smaller the denominator, the greater is the value of the fraction if the numerator remains the same. The larger the denominator, the less is the value of the fraction if the numerator remains the same. 6. Compare and 1. 7. Compare and . 8. Compare and 1. 9. If the denominator be doubled (e.g. 2 x 3 = 6) how will the value of the fraction be affected? 1/6 4. If the numerator be doubled, how will the value of the fraction be affected? Changing Fractions to Higher Terms 1. How many fourths in ? 2. How many sixths in ? 3. How many eighths in? 4. How many tenths in ? Ө If we write the answers in a table, we have: = A. 4. Compare the two denominators C. D. 1 = 10. We might have obtained these results (without using pictures) by multiplying both the numerator and the denominator of by the same number. This operation is called the reduction of fractions to higher terms. In, the new numerator 3 is "higher" (or greater) than the old numerator, and the new denominator 6 is "higher" (or greater) than the old denomi nator. By changing the numerator from 1 to 3, we get 3 times as many parts; but at the same time we change the denominator from 2 to 6, so that the parts are only one third as large. The change in the numerators is offset or balanced by the change in the denominators. PRINCIPLE. Multiplying both terms of a fraction by the same number does not change the value of the fraction. 1 ? = 6 12 ORAL EXERCISE 1. What number must 6 be multiplied by to produce 12? 2. What operation must be performed on the numerator to keep the value of the fraction unchanged? |