Answer Key
CHAPTER 3 Subtraction of Whole Numbers
Lesson 1
On The Road to Learning (pages 164 and 165)
A.
1. 7 3. 8 5. 7
2. 5 4. 2 6. 1
B. 1. 10 – 4 = 6 2. 9 – 6 = 3
C. Check also the number of items crossed out.
1. 6 (3 balloons)
2. 6 (4 stars)
On The Road to Learning (page 166)
A.
1. 3 3. 2 5. 7
2. 4 4. 1 6. 5
B. 1. 5 2. 3
On The Road to Learning (page 168)
A.
1. 10 , 9 4. 10 , 5
2. 9 , 4 5. 9 , 5
3. 7 , 3
B. Answers may vary. Possible answers:
1. 7 + 3 = 10
10 – 3 = 7
2. 5 + 4 = 9
9 – 4 = 5
3. 6 + 2 = 8
8 – 2 = 6
On The Road to Learning (pages 169 and 170)
A.
1. 3 + 7 = 10 10 – 3 = 7
7 + 3 = 10 10 – 7 = 3
2. 6 + 2 = 8 8 – 2 = 6
2 + 6 = 8 8 – 6 = 2
3. 4 + 6 = 10 10 – 4 = 6
6 + 4 = 10 10 – 6 = 4
B.
1. 9 + 2 = 11 11 – 2 = 9
2 + 9 = 11 11 – 9 = 2
2. 8 + 4 = 12 12 – 4 = 8
4 + 8 = 12 12 – 8 = 4
Creating My Math Word Corner (page 171)
Sample answers: subtraction, minuend, subtrahend, difference, minus, related facts, opposite operations
Showing What I Have Learned
Hitting the Mark (pages 171 and 172)
A.
1. 2 5. 2 9. 4
2. 7 6. 4 10. 2
3. 10 7. 6 11. 3
4. 1 8. 0 12. 4
B.
Going Beyond the Mark (page 172)
1. 4 players are still running.
2. There are 6 bags left.
3. Answer may vary. Possible answer:
Josh has 8 pencils. He gave his two pencils to his younger brother. How many pencils were left? 8 – 2 = 6
Understanding How I Learned (page 173)
Answers may vary. Sample answers:
1. The part of the lesson I found interesting was the relationship of addition and subtraction as opposite operations.
2. I now know better how to do subtraction of numbers.
3. The new things I learned are the parts of a subtraction sentence and how to do subtraction of numbers.
1. 4 players are still running.
2. There are 6 bags left.
3. Answer may vary. Possible answer:
Josh has 8 pencils. He gave his two pencils to his younger brother. How many pencils were left? 8 – 2 = 6
Understanding How I Learned (page 173)
Answers may vary. Sample answers:
1. The part of the lesson I found interesting was the relationship of addition and subtraction as opposite operations.
2. I now know better how to do subtraction of numbers.
3. The new things I learned are the parts of a subtraction sentence and how to do subtraction of numbers.