## Engage NY Eureka Math 1st Grade Module 1 Lesson 21 Answer Key

### Eureka Math Grade 1 Module 1 Lesson 21 Problem Set Answer Key

Add the numbers on the pairs of cards. Write the number sentences. Color doubles red. Color doubles plus 1 blue.

Question 1.

Answer: 6

The above equation shows a pair of cards

ADD the pair of cards

By adding 3 and 3

we get 6

Question 2.

Answer:8

The above equation shows a pair of cards

ADD the pair of cards

By adding 4 wth 4

we get 8

Question 3.

Answer:7

The above equation shows a pair of cards

ADD the pair of cards

By adding 3 wth 4

we get 7

Question 4.

Answer:9

The above equation shows a pair of cards

ADD the pair of cards

By adding 5 wth 4

we get 9

Solve. Use your doubles to help. Draw and write the double that helped.

Question 5.

Answer: 9

Given the numbers are 5 and 4

To find the missing number

Add 5 with 4

we get 9

Question 6.

Answer:7

Given the numbers are 3 and 4

To find the missing number

Add 3 with 4

we get 7

Question 7.

Solve the doubles and the doubles plus 1 number sentences.

Answer:

Question 8.

Show how this strategy can help you solve 5 + 6 =

Answer:11

Given the numbers are 5 and 6

To find the missing number

Add 5 with 6

we get 11

Question 9.

Write a set of 4 related addition facts for the number sentences of Problem 7(d).

Answer: 4+4 =8

8+4+4

4+5=9

9=4+5

### Eureka Math Grade 1 Module 1 Lesson 21 Exit Ticket Answer Key

Write the double and double plus 1 number sentence for each 5-group card.

Answer:

### Eureka Math Grade 1 Module 1 Lesson 21 Homework Answer Key

Question 1.

Draw the 5-group card to show a double. Write the number sentence to match the cards.

a.

Answer:The double fact that hlped to solve the euqation is

4+4=8

For which the double+1 fact is 4+5=9

b.

Answer:The double fact that hlped to solve the euqation is

3+3=6

For which the double+1 fact is 3+4=7

c.

Answer:The double fact that hlped to solve the euqation is

5+5=10

For which the double+1 fact is 5+6=11

Question 2.

Fill in the 5-group cards in order from least to greatest, double the number, and write the number sentences.

a.

b.

c.

d.

e.

Answer:

Question 3.

Solve the number sentences.

a. 3 + 3 = __

Answer:6

Given : two numbers are 3 and 3

By adding 3 with 3 we get 6

3 + 3 = 6

b. 5 + __ = 10

Answer:10

Given : two numbers are 5 and 10

by subracting 5 from 10 we get 5

10-5=5

so the issing number is 5

5 + 5 = 10

c. 1 + __ = 2

Answer: 1

Given : two numbers are 1 and 2

by subracting 1 from 2 we get 1

2-1=1

so the issing number is 1

1+1=2

d. 4 = __ + 2

Answer:2

Given : two numbers are 4 and 2

by subracting 2 from 4 we get 2

4-2=2

so the issing number is 2

4 = 2 + 2

e. 8 = 4 + __

Answer:4

Given : two numbers are 4 and 8

by subracting 4 from 8 we get4

8-4=4

so the issing number is 5

8 = 4 + 4

Question 4.

Match the top cards to the bottom cards to show doubles plus 1.

a.

b.

c.

d.

Answer:

Question 5.

Solve the number sentences. Write the double fact that helped you solve the double plus 1.

a.

Answer: The double +1 fact that hlped to solve the euqation is

2+3=5

For which the double fact is 2+2=4

b.

Answer:The double +1 fact that hlped to solve the euqation is

3+4=7

For which the double fact is 3+3=6

c.

Answer:The double +1 fact that hlped to solve the euqation is

4+5=9

For which the double fact is 4+4=8