All the solutions provided inÂ **McGraw Hill My Math Grade 1 Answer Key PDF Chapter 2 Lesson 13 Relate Addition and Subtraction **will give you a clear idea of the concepts.

## McGraw-Hill My Math Grade 1 Answer Key Chapter 2 Lesson 13 Relate Addition and Subtraction

**Explore and Explain**

Answer:

Explanation:

There are 3 birds in the bird bath

2 more birds join them

The addition fact to solve the problem is 3 + 2 = 5

The related subtraction fact is 5 – 3 = 2

So, there are 5 birds in all.

**Teacher Directions:** Use to model. There are 3 birds in the bird bath. 2 more birds join them. Write the addition number sentence to show how many birds there are in all. Write a related subtraction number sentence.

**See and Show**

Related facts use the same numbers. These facts can help you add and subtract

5 + 2 = 7

7 – 5 = 2

7 – 2 = 5

**Helpful Hint**

5 + 2 = 7.

Use that fact to find

7 – 2 = 5.

You can use __5__ + __2__ = __7__

to find __7__ – __2__ = __5__

They are opposite or inverse operations.

**Identify an addition fact. Use Work Mat 3 and to find a related subtraction fact. Write both facts.**

Question 1.

____ + ____ = _____

____ – ____ = _____

Answer:

3 + 6 = 9

9 – 3 = 6

Explanation:

The addition fact for the given picture is 3 + 6 = 9

The related subtraction fact is 9 – 3 = 6.

Question 2.

____ + ____ = _____

____ – ____ = _____

Answer:

2 + 4 = 6

6 – 2 = 4

Explanation:

The addition fact for the given picture is 2 + 4 = 6

The related subtraction fact is 6 – 2 = 4.

**Talk Math** How can addition facts help you subtract? Explain.

Answer:

We can use addition fact to subtract by subtracting one of the addend from the sum.

**On My Own**

**Use Work Mat 3 and to find the related subtraction facts. Write the facts.**

Question 3.

5 + 4 = 9

____ – ____ = ____

____ – ____ = ____

Answer:

9 – 4 = 5

9 – 5 = 4

Explanation:

The related subtraction facts for the given addition facts are 9 – 4 = 5 and 9 – 5 = 4.

Question 4.

8 + 1 = 9

____ – ____ = ____

____ – ____ = ____

Answer:

9 – 1 = 8

9 – 8 = 1

Explanation:

The related subtraction facts for the given addition facts are 9 – 1 = 8 and 9 – 8 = 1.

Question 5.

1 + 4 = 5

____ – ____ = ____

____ – ____ = ____

Answer:

5 – 1 = 4

5 – 4 = 1

Explanation:

The related subtraction facts for the given addition facts are 5 – 1 = 4 and 5 – 4 = 1.

Question 6.

3 + 4 = 7

____ – ____ = ____

____ – ____ = ____

Answer:

7 – 3 = 4

7 – 4 = 3

Explanation:

The related subtraction facts for the given addition facts are 7 – 3 = 4 and 7 – 4 = 3.

Question 7.

5 + 3 = 8

____ – ____ = ____

____ – ____ = ____

Answer:

8 – 5 = 3

8 – 3 = 5

Explanation:

The related subtraction facts for the given addition facts are 8 – 5 = 3 and 8 – 3 = 5.

Question 8.

2 + 3 = 5

____ – ____ = ____

____ – ____ = ____

Answer:

5 – 2 = 3

5 – 3 = 2

Explanation:

The related subtraction facts for the given addition facts are 5 – 2 = 3 and 5 – 3 = 2.

**Problem Solving**

**Write a subtraction number sentence. Then write a related addition fact.**

Question 9.

There are 8 lizards. 6 of the lizards run away. How many lizards are left?

____ – ____ = ____ lizards

____ + ____ = ____

Answer:

8 – 6 = 2 lizards

6 + 2 = 8

Explanation:

There are 8 lizards

6 of the lizards run away

The subtraction fact to solve the problem is 8 – 6 = 2

The addition fact for the problem is 6 + 2 = 8

So, 2 lizards are left.

Question 10.

Chad saw 7 birds. Audrey saw 4 birds. How many more birds did Chad see?

____ – ____ = ____ birds

____ + ____ = ____

Answer:

7 – 4 = 3 birds

4 + 3 = 7

Explanation:

Chad saw 7 birds

Audrey saw 4 birds

The subtraction fact to solve the problem is 7 – 4 = 3

The addition fact for the problem is 4 + 3 = 7

So, Chad see 3 more birds.

**Write Math** 5 + 4 = 9 and 9 – 3 = 6. Are these related facts? Explain why or why not.

______________________

______________________

______________________

______________________

Answer:

5 + 4 = 9 and 9 – 3 = 6

No, these are not related facts

In related facts the facts will have same numbers.

### McGraw Hill My Math Grade 1 Chapter 2 Lesson 13 My Homework Answer Key

**Practice**

**Identify an addition fact. Write a related addition and subtraction fact.**

Question 1.

____ + ____ = _____

____ – ____ = _____

Answer:

4 + 3 = 7

7 – 4 = 3

Explanation:

The addition fact for the given picture is 4 + 3 = 7

The related subtraction fact is 7 – 4 = 3.

Question 2.

____ + ____ = _____

____ – ____ = _____

Answer:

3 + 5 = 8

8 – 3 = 5

Explanation:

The addition fact for the given picture is 3 + 5 = 8

The related subtraction fact is 8 – 3 = 5.

**Find the related subtraction facts. Write the facts.**

Question 3.

4 + 2 = 6

____ – ____ = _____

____ – ____ = _____

Answer:

6 – 2 = 4

6 – 4 = 2

Explanation:

The related subtraction facts for the given addition facts are 6 – 2 = 4 and 6 – 4 = 2.

Question 4.

1 + 8 = 9

____ – ____ = _____

____ – ____ = _____

Answer:

9 – 1 = 8

9 – 8 = 1

Explanation:

The related subtraction facts for the given addition facts are 9 – 1 = 8 and 9 – 8 = 1.

**Write the subtraction number sentence. Then write the related addition fact.**

Question 5.

There are 6 flowers in a vase. Mom gives 2 of the flowers to a friend. How many flowers are in the vase now?

____ – ____ = ____

____ + ____ = ____

Answer:

6 – 2 = 4

4 + 2 = 6

Explanation:

There are 6 flowers in a vase

Mom gives 2 of the flowers to a friend

6 – 2 = 4

The subtraction fact to solve the problem is 6 – 2 = 4

The addition fact for the problem is 4 + 2 = 6.

**Vocabulary Check**

**Circle the correct answerÂ **

subtractÂ Â Â Â Â related facts

Question 6.

3 + 1 = 4 and 4 – 1 = 3 are ______

Answer:

related facts

Explanation:

3 + 1 = 4 and 4 – 1 = 3 are related facts.

**Math at Home** Write an addition or subtraction number sentence using numbers 1-9. Have your child write a related addition or subtraction fact.