PROBLEM WORK 27 problem: I have 9 apples; John has 6. What is the difference of 9 and 6? Whenever you need to do any one of these things, you should subtract. The answer in a subtraction example has its own name. The name is the difference. You will need to know what difference means in arithmetic; so be sure to remember it. (WRIT 22. Problems in Addition and Subtraction. TEN WORK.) Before you try to get the answers to these problems, be sure you know whether you are to add or subtract. 1. The third-grade children of Whittier School went on a bird hike. They saw two chickadees, two downy woodpeckers, and five robins. (a) How many birds did they see? (b) How many different kinds of birds did they see? 2. The boys played an addition game with the girls in the third grade. They kept their scores in this way: Whose was the higher score, the boys' or the girls'? 3. Marbles cost five cents for three. Frank had eight marbles and bought five cents' worth. How many did he then have? 4. Sam's grandmother lived six blocks from his home. He often went there on his roller skates. How many blocks did he skate, going there and coming back home? 5. The children of the third grade had eight goldfish. Two of them died. How many were left? 6. Helen sent 8 invitations for her birthday party. Five girls came to the party. How many of the girls who were invited did not come? 7. Jim had to work 9 arithmetic examples. He finished 5. How many more did he have to do? EXTRA PROBLEMS FOR GOOD WORKERS 8. Alice and Paul went to the circus with their father. They saw five elephants, two camels, three lions, a leopard, and two giraffes. (a) How many different kinds of animals did they see? (b) How many animals did they see in all? 9. Paul spent 5 cents for peanuts to feed the elephants, 5 cents for popcorn, and 10 cents for a balloon. How much money did he spend? 10. The tickets for a merry-go-round were ten cents each. How much did it cost for Alice, Paul, and their father to ride on the merry-go-round? REVIEW OF ARITHMETIC WORDS 29 23. Review of Words Used in Arithmetic. (WRITTEN WORK.) It will be fun to see if you can remember the new arithmetic words you have learned. Study this article carefully. Try to give the answers without making a mistake. 1. Is 39 smaller or larger than 41? 2. Add five and two. 3. The answer in addition is called the 4. Write the plus sign. 5. Show how you can save time in writing this example: three and one are four. 6. Why is it a good plan to use signs? 7. Write 6 and 3 in a column and find the sum. 8. Write the figure for the word seven. 9. If you add zero to 6, what is the sum? 10. Subtract one from four. 11. To find the sum of two numbers you 12. When you take one number away from another number, you.---------- 13. The answer in subtraction is the 14. To find the difference of two numbers you..... 15. When you have one number and want to know how many more you need to make another number, you MINUENDS LESS THAN 10.* (No Zero Difficulties) 24. Getting Ready to Use the 36 Easy Subtraction Facts. (ORAL PRACTICE.) Give the numbers that belong on the blanks on this page and the next. Give the differences: (4) 1. 1 from 2 is...... 2. 1 from 3 is...... 3. 1 from 4 is...... 4. 3 from 6 is...... 5. 1 from 6 is.... 6. 6 from 7 is...... 7. 1 from 7 is...... EXERCISE 1 (B) 2 from 3 is...... (C) 2 from 4 is...... 1 from 5 is...... 8. 7 from 8 is...... 9. 1 from 8 is...... 10. 4 from 8 is. 11. 2 from 7 is...... 12. 2 from 9 is...... 4 from 9 is...... EXERCISE 2 25. Practice on the 36 Easy Subtraction Facts. (ORAL WORK.) You have learned that numbers to be added may be written in different ways. This is true of subtraction examples, also. EXAMPLE. If you had 6 cents and spent 2 cents, how many cents would you have left? To subtract, put the smaller number 6¢ under the larger one like this: and then subtract. The answer is 4 cents. 2¢ 4¢ Subtract and give the differences in the examples in the four rows on this page and the next. Watch to see if any mistakes are made. If you cannot give the answers quickly, turn to page 370, and practice until you can. |