SUBTRACTION - LESSON A 15. 1. Memorize the following: The exercise at the right is read, 6 and how many are 10? The answer is 2. Read the above exercises, beginning at the right. 3. Give a number story suggested by each. MODEL: Fred had 10 apples. He gave 6 of them to James. Fred had - apples left. 16. Oral Problems. 1. Four books and 2. Two days and 3. Nine months and books are nine books. days are five days. months are twelve months. 4. Five chairs are three chairs and — chairs. 5. Ten weeks are six weeks and 6. Nine boys are four boys and them were seated. weeks. boys. Three of 7. There were five girls in a room. How many were not seated? five apples. He gave away two apples left. 8. A boy had apples. He had 9. There were ten words on the blackboard. Lottie erased six of the words. were left on the blackboard? How Study the above exercises until you can give the answers as readily as you can read these numbers: 2. 125 109 124 105 129 103 122 100 120 -93-44-32-60-30-43-92 19. Written Exercises. - 40 - 90 In Exercise a below, the 9 is greater than the 2 above it, so we say 9 and 3 are 12. We then add 1 to the next lower number. This changes it to 3. We then say 3 and 2 are 5. 2. α 55 100 in. с e 90 ft. 50 yd. 102 gal. - $23-36 in. -46 ft. - 30 yd. - 59 gal. d f 44 in. ADDITION AND SUBTRACTION-LESSON A 20. Oral Problems. 1. A boy paid $3 for a pair of shoes and $2 for a hat. How much did he pay for both? 2. Nine ducks were swimming on a pond. Five flew away. How many ducks were left on the pond? 3. A boy threw at a mark. He missed it 6 times. and struck it 4 times. How many times did he throw? 4. Twelve girls were invited to a party. Three of the girls were not able to go. How many girls went to the party? 5. A boy spent part of his vacation in camping out and the rest of it in the city. He camped for 9 weeks and was in the city 3 weeks. How long was his vacation? 6. A girl had a ribbon 5 yards long. She cut off a piece 2 yards long. How long was the part that was left? 7. A boy had 10 cents. He bought a tablet for 4 cents. How much money did he have left? 8. If it takes 2 yards of cloth to make an apron, how many yards will it take to make two aprons? What is the answer in addition called? The answer in subtraction is called the difference, or remainder. 21. Written Exercises. Begin with Exercise a and add the right-hand column, thus: 9, 12, 14. Write the 4 under the column. Add the 1 to the 1 at the foot of the next column, and add: 2, 4, 9, 12. 24. Written Problems. 1. A man bought a horse for $90 and a harness for $30. How much did he pay for both? 2. There were 59 ducks on a pond. Twenty-five How many ducks were left on of them flew away. the pond? MODEL FOR ADDITION $90 cost of horse +$30 cost of harness $120 cost of both MODEL FOR SUBTRACTION 59 ducks on pond -25 ducks flew away 34 ducks left on pond 3. There are 23 girls in Room A and 32 girls in Room B. How many girls are there in both rooms? 4. There were 55 pupils in a room. pupils left the room. the room? Thirty-two How many pupils remained in 5. A boy had 95 cents. He spent 50 cents. How much money had he left? 6. A farmer had 29 cows. He bought 23 cows. How many cows did he then have? 7. Fred has 23 marbles. James has 32 marbles. How many marbles have both? 8. A man bought a wagon for $50 and a team of horses for $240. How much did both cost him? 9. A grocer sold 62 pounds of sugar on Monday and 43 pounds on Tuesday. How many pounds did he sell on both days? |