SUBTRACTION 1. From 83 subtract 5. 838 tens + 3 ones, or 7 tens + 13 ones 5= 78= 5 ones .7 tens + 8 ones Since 5 ones cannot be taken from 3 ones, take 1 ten (=10 ones) from the 8 tens (leaving 7 tens) and add it to the 3 ones, making 13 ones. 13 ones less 5 ones equal 8 ones. 7 tens (remaining) less 0 tens equal 7 tens. The work may be expressed thus: We think: "5 from 13 leaves 8; 0 from 7 leaves 7; 78." Test. 78+5=83. Subtract, and test each result: 713 83 5 78 PRACTICAL PROBLEMS 1. A dairyman had 31 quarts of milk. He sold 9 quarts to a baker. How many quarts had he left? 2. Frank's garden contained 72 square feet of land. A small bed of radishes covered 9 square feet of the garden. How many square feet of the garden were left for other vegetables? 3. A coat and a hat together cost 80 dollars. The hat cost 9 dollars. What was the cost of the coat? 4. A farmer had 41 cows. He sold them all but 9. How many cows did he sell? 5. Hazel had 63 cents. She mailed 4 letters, placing a 2-cent stamp on each. How much money had she left when she had paid for the stamps? 6. Katherine bought a box of crayons for 8 cents. How much had she left from half a dollar? 7. A grocer sold 9 quarts of molasses from a keg containing 40 quarts. How many quarts were left? 8. What number must be added to 9 to make 72? 9. Find the difference between 62 and 8. 10. The larger number is 91, the smaller number is 7. What is the remainder? 11. Subtract 9 from 71. 12. Take 6 from 63. 13. A man had 50 dollars. He paid 9 dollars for a railroad ticket. How many dollars had he left? UNITED STATES MONEY United States money is written in dollars and cents. A period (.), named a "decimal point," is placed to the right of dollars. After the point, cents are written in two places. Thus, 5 dollars and 25 cents is written $5.25; 5 cents is written $.05, 42 cents, $.42. 1. Read: $8.40; $9.67; $3.14; $8.24; $7.05. In addition and subtraction of United States money, the point must be written under the point, dollars under dollars, and cents under cents. HALVES AND THIRDS OF NUMBERS 1. How many tens make twenty? One ten is what part of 20? One half of twenty is ten. One half of four is two. What is one half of twenty-four? 2. of 20=10 of 26 = 13. of 6= 3 3. Find in the same way of 28. 4. How many sevens are twenty-one? One seven is what part of twenty-one? of 21 = 7. 5. How many eights are 24? One eight is what part of 24?of 24 = 8. 6. How many are three nines? One nine is what part of 27?of 27=9. 7. How many tens are thirty? How much is of 30? 8. Find of 36 by finding of 30 and 3 of 6. 9. If I divide 39 cents equally among 3 boys, how much will each receive? 10. Susan divided 27 roses equally among 3 girls. How many did each receive? 11. Helen, May, and Ned divided 21 quarts of berries equally. How many did each receive? MULTIPLYING BY 2 1. Review the table of 2's to 2 x 10. ¢ 5. How many are two 34's? 2× 34 =? 321 34 2 68 34¢ 6. A short process of finding two 34's is as follows: Write the 2 under the right-hand figure of the number to be multiplied, which is 34. Beginning at the right, say 2× 4-8. Write 8 in ones' place in the answer. 2 x 3 6. Write 6 in tens' place in the answer. Test by addition, 34 +34 68. Multiply: b = = The result is 68. 2 68¢ a 7. 23 54 |