Page 61 - TG_G1_CH6_CHRIS

Name Date
C. Add or subtract.
Lesson 9: Think Addition to Subtract Tens 1 80 subtract 20 = 60 5 50 add 10 = 60
A. Write the missing number. Use related facts to add and
subtract.
1 30 + 40 = 70 3 20 + 60 = 80 2 30 minus 10 = 20 6 40 plus 30 = 70
70 – 30 = 40 80 – 60 = 20
3 40 less than 90 = 50 7 60 more than 30 = 90
70 – 40 = 30 80 – 20 = 60

2 40 – 30 = 10 4 50 + 30 = 80 4 Take 50 away from 60 = 10 8 Add 20 to 20 = 40
30 + 10 = 40 80 – 50 = 30 D. Problem solving.
B. Match. 1 There are 40 butterflies. 2 There are 60 butterflies.
20 butterflies join them. 20 butterflies fly away.
20 + ________ = 50 50
How many altogether? 60 How many are left? 40

70 – ________ = 60 20

________ – 40 = 40 80

________ + 50 = 70 10

90 – ________ = 40 30
118 Chapter 6
Chapter 6 117

Practice Book, p. 117 Practice Book, p. 118

Name Date Name Date
Lesson 9: Think Addition to Subtract Tens Lesson 9: Think Addition to Subtract Tens
A. Write the missing numbers.
Reteach
1 30 + 40 = 70 2 15 + 5 = 20
70 20 50 + 40 = 90
70 – 30 = 40 20 – 5 = 15 90
90 - 50 = 40
30 40 15 5
70 – 40 = 30 20 – 15 = 5 50 40
90 - 40 = 50
3 4
10 + 30 = 40 20 + 60 = 80
40 80 Use the model to add and subtract.
40 – 10 = 30 80 – 20 = 60
10 30 20 60
40 – 30 = 10 80 – 60 = 20 1 3
50 + 30 = 80 20 + 10 = 30
B. Solve.
80 30
1 I am a number that is 30 more than 20. What number am I? 80 - 50 = 30 30 - 20 = 10
20 + 30 = 50 50 30 80 - 30 = 50 20 10 30 - 10 = 20
C. Problem Solving
There are 60 apples in a box. 10 of the apples are red and the rest
are yellow. Charlotte says that there are 40 yellow apples. Is she
correct? Write an addition sentence to justify your answer.
She is incorrect. 2 30 + 20 = 50 4 40 + 20 = 60
60 = 10 + 50, 60 – 10 = 50 yellow apples 50 60
50 - 30 = 20 60 - 40 = 20
30 20 50 - 20 = 30 40 20 60 - 20 = 40

Chapter 6 - Enrich 59 Chapter 6 - Reteach 59
Enrich Practice Book, p. 59 Reteach Practice Book, p. 59
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