2. Tom had 85 paper sacks in the morning. He used 43 that day. How many sacks did he have left? What does the problem ask for? This is the way to work it: Write the smaller number under it. You can do it, can't you? difference? →85 Then 43 subtract. What is the answer, or 3. He asked another boy to take care of his stand in the afternoon while he went around to see some things at the circus. He took 65 cents with him. He spent 30 cents. How much did he bring back? Read the problem again to be sure your answer is the correct one. Subtract: 65¢ (B) HOW MANY OR HOW MUCH MORE? 30¢ 4. A boy whose father was a gardener helped get vegetables ready to sell at the market. He pulled radishes and tied them into bunches. His father wanted 48 bunches one day. The boy had tied only 25. How many more bunches did he need? 5. Ruth had 60 cents and wanted to buy a baby doll that cost 89 cents. How much more money did she need? 6. Ruth's mother bought some ribbon for 52 cents and gave the clerk 75 cents. How much change should she have received? SUBTRACTION PRACTICE (C) WHAT IS THE DIFFERENCE? 43 7. One toy costs 76 cents. Another costs 32 cents. What is the difference in the cost of these toys? 8. Harry weighs 72 pounds. Dick weighs 87 pounds. What is the difference of their weights? 9. James rode his bicycle 67 miles one week, and Dick rode his 44 miles. What is the difference of the distances the boys rode? 34. Practice in Subtracting Larger Numbers. (ORAL AND WRITTEN WORK.) Be sure that you copy the examples in this lesson very carefully; then subtract. 35. Problems in Subtraction. (WRITTEN WORK.) Here are some problems that will show you whether you can subtract larger numbers. If she buys a doll for 25 cents, will she have enough money left to buy a bed that costs 50 cents? 3. How many stories high is the building in the picture? There is one row for each story. 4. Tom's father works on the 5th floor, and Fred's father works on the 9th floor. When Tom and Fred go to their fathers' offices, how many stories higher in the elevator must Fred ride than Tom? 5. One night Carl's mother told him that when he had counted 10 houses with lights in them he could turn on the light in their FINDING AND CORRECTING ERRORS 45 own house. When Carl had counted 7 lights, his mother said, "How many more must you count?" What should Carl have said? 6. The pupils in a third-grade class were being weighed at school. Clara, the lightest girl, weighed 41 pounds. Marie, the heaviest girl, weighed 57 pounds. How much more did Marie weigh than Clara? 7. Paul weighed 67 pounds. How much lighter than Paul was Carl, who weighed 46 pounds? 8. How much heavier was Paul than Marie? 9. How much lighter was Clara than Paul? 36. Finding and Correcting Errors in Addition and Subtraction. (A SILENT READING LESSON.) Answers are given to the 15 examples below. Some of these answers are right and some are wrong. Write on your paper the number of each example. If the answer for the example is correct, put a “C” after its number. If the answer is not right, write the correct answer after the number. This is the way to do the work for the first two examples: 1. C Finish the work quickly. Then your 2. 10 teacher may ask you to read what you have on your paper. 1. 4+7=11 6. 87-23=64 8. 1-0-10 10. 7+9=16 11. 8+9=18 12. 88-53-25 37. Problems in Subtraction. (WRITTEN WORK.) Read the problems carefully to be sure you know what each one asks for. 1. Nineteen boys were playing in Jack's yard; 14 went home. How many boys were in the yard then? 2. Billy had 14 marbles in the morning, but by noon he had lost some. He had six left. How many had he lost? . 3. Jean had 32 cents. She spent 13 cents for a pencil. How many cents did she have left? 4. Helen spent 10 cents to mail a box and a letter. It cost 2 cents to mail the letter. How much did it cost to mail the box? 5. Billy's hen had 13 little chickens. One morning after a storm, he found six of them dead. How many little chickens were alive? 6. Jim played at Jack's house from 3 o'clock until 5 one day. How many hours did Jim play at Jack's house that day? 7. Mabel is 9 years old. Her sister Ruth is 2 years younger. How old is Ruth? SUMMARY 38. General Review. (WRITTEN WORK.) Be sure that you can give the differences in all of the 100 subtraction examples on pages 38 and 39 without mistakes. If you know how to give these differences quickly, your arithmetic work will be easier for you. |