All the solutions provided inÂ **McGraw Hill My Math Grade 1 Answer Key PDF Chapter 4 Lesson 2 Use a Number Line to Subtract **will give you a clear idea of the concepts.

## McGraw-Hill My Math Grade 1 Answer Key Chapter 4 Lesson 2 Use a Number Line to Subtract

**Explore and Explain**

Answer:

Explanation:

A store has 11 beach balls to sell

It sells 2 of them

I used number line to subtract

Start at 11

Count back 2

10, 9

So, 11 – 2 = 9

So, 9 beach balls are left.

**Teacher Directions:** Use a paper clip to count back on the number line. A store has 11 beach balls to sell. It sells 2 of them. How many beach balls do they have left? Write the number.

**See and Show**

You can use a number line to subtract.

9 – 3 = __6__

**Helpful Hint**

Start at 9. Count back 3 to find the difference. 9, 8, 7, 6.

**Use the number line to subtract Show your work. Write the difference.**

Question 1.

8 – 2 = ____

Answer:

Explanation:

I used number line to subtract

Start at 8

Count back 2

7, 6

So, 8 – 2 = 6.

Question 2.

10 – 3 = ____

Answer:

Explanation:

I used number line to subtract

Start at 10

Count back 3

9, 8, 7

So, 10 – 3 = 7.

Question 3.

5 – 1 = ____

Answer:

Explanation:

I used number line to subtract

Start at 5

Count back 1

4

So, 5 – 1 = 4.

Question 4.

12 – 3 = ____

Answer:

Explanation:

I used number line to subtract

Start at 12

Count back 3

11, 10, 9

So, 12 – 3 = 9.

**Talk Math**

Can you only use the number line to help you subtract numbers? Explain.

Answer:

Yes, one can do addition and subtraction on a single number line. For example, 3 + 3Â need to represent by a number line, then we first take the number 3 on the number line. After that move towards the right with 3 units as the addition takes place.

**On My Own**

**Use the number line to help you subtract. Write the difference.**

Question 5.

Answer:

Explanation:

I used number line to subtract

Start at 8

Count back 3

7, 6, 5

So, 8 – 3 = 5.

Question 6.

Answer:

Explanation:

I used number line to subtract

Start at 7

Count back 3

6, 5, 4

So, 7 – 3 = 4.

Question 7.

Answer:

Explanation:

I used number line to subtract

Start at 10

Count back 2

9,

So, 10 – 2 = 8.

Question 8.

Answer:

Explanation:

I used number line to subtract

Start at 6

Count back 2

5, 4

So, 6 – 2 = 4.

Question 9.

Answer:

Explanation:

I used number line to subtract

Start at 7

Count back 1

6

So, 7 – 1 = 6.

Question 10.

Answer:

Explanation:

I used number line to subtract

Start at 11

Count back 3

10, 9, 8

So, 11 – 3 = 8.

Question 11.

12 – 1 = ____

Answer:

Explanation:

I used number line to subtract

Start at 12

Count back 1

11

So, 12 – 1 = 11.

Question 12.

9 – 2 = ____

Answer:

Explanation:

I used number line to subtract

Start at 9

Count back 2

8, 7

So, 9 – 2 = 7.

Question 13.

10 – 1 = ____

Answer:

Explanation:

I used number line to subtract

Start at 10

Count back 1

9

So, 10 – 1 = 9.

Question 14.

11 – 2 = ____

Answer:

Explanation:

I used number line to subtract

Start at 11

Count back 2

10, 9

So, 11 – 2 = 9.

Question 15.

5 – 3 = ____

Answer:

Explanation:

I used number line to subtract

Start at 5

Count back 2

4, 3, 2

So, 5 – 3 = 2.

Question 16.

10 – 3 = ____

Answer:

Explanation:

I used number line to subtract

Start at 10

Count back 3

9, 8, 7

So, 10 – 3 = 7.

Question 17.

12 – 2 = ___

Answer:

Explanation:

I used number line to subtract

Start at 12

Count back 2

11, 10

So, 12 – 2 = 10.

Question 18.

7 – 2 = ____

Answer:

Explanation:

I used number line to subtract

Start at 7

Count back 2

6, 5

So, 7 – 2 = 5.

**Problem Solving**

Question 19.

Ava sees 12 sharks. 2 of them swim away. How many sharks does Ava see now?

____ sharks

Answer:

Explanation:

Ava sees 12 sharks

2 of them swim away

I used number line to subtract

Start at 10

Count back 2

11, 10

So, 12- 2 = 10

Ava sees now 10 sharks.

Question 20.

There are 11 manatees near the shore. 3 of them swim away. How many manatees are still near the shore?

____ manatees

Answer:

Explanation:

There are 11 manatees near the shore

3 of them swim away

I used number line to subtract

Start at 11

Count back 3

10, 9, 8

So, 11 – 3 = 8

8 manatees are still near the shore.

**Write Math** How do you use a number line help you subtract? Explain.

______________________

______________________

______________________

______________________

Answer:

Subtraction on a number line is done by the counting logic. To subtract a positive number, we move towards the left-hand side of the number line. For example, 6 – 2 can be calculated by taking 6 as the starting number and moving 2 units towards the left on a number line which gives the result as 4.

### McGraw Hill My Math Grade 1 Chapter 4 Lesson 2 My Homework Answer Key

**Practice**

**Use the number line to subtract. Show your work. Write the difference.**

Question 1.

10 – 3 = ____

Answer:

Explanation:

I used number line to subtract

Start at 10

Count back 3

9, 8, 7

So, 10 – 3 = 7.

Question 2.

6 – 2 = ____

Answer:

Explanation:

I used number line to subtract

Start at 6

Count back 2

5, 4

So, 6 – 2 = 4.

Question 3.

12 – 3 = ____

Answer:

Explanation:

I used number line to subtract

Start at 12

Count back 3

11, 10, 9

So, 12 – 3 = 9.

Question 4.

5 – 2 = ____

Answer:

Explanation:

I used number line to subtract

Start at 5

Count back 2

4, 3

So, 5 – 2 = 3.

**Use the number line to help you subtract. Write the difference.**

Question 5.

11 – 2 = ____

Answer:

Explanation:

I used number line to subtract

Start at 11

Count back 2

10, 9

So, 11 – 2 = 9.

Question 6.

6 – 1 = ____

Answer:

Explanation:

I used number line to subtract

Start at 6

Count back 1

5

So, 6 – 1 = 5.

Question 7.

9 – 3 = ____

Answer:

Explanation:

I used number line to subtract

Start at 9

Count back 3

8, 7, 6

So, 9 – 3 = 6.

Question 8.

12 – 1 = ____

Answer:

Explanation:

I used number line to subtract

Start at 12

Count back 1

11

So, 12 – 1 = 11.

Question 9.

Answer:

Explanation:

I used number line to subtract

Start at 6

Count back 1

5

So, 6 – 1 = 5.

Question 10.

Answer:

Explanation:

I used number line to subtract

Start at 7

Count back 3

6, 5, 4

So, 7 – 3 = 4.

Question 11.

Answer:

Explanation:

I used number line to subtract

Start at 8

Count back 2

7, 6

So, 8 – 2 = 6.

Question 12.

There are 10 sharks swimming. 2 of the sharks swim away. How many sharks are still swimming?

_______ sharks

Answer:

Explanation:

There are 10 sharks swimming

2 of the sharks swim away

I used number line to subtract

Start at 10

Count back 2

9, 8

So, 10 – 2 = 8

8 sharks are still swimming.

**Test Practice**

Question 13.

10 – 3 = ____

(A) 0

(B) 3

(C) 7

(D) 8

Answer:

Explanation:

I used number line to subtract

Start at 10

Count back 3

9, 8, 7

So, 10 – 3 = 7.

**Math at Home** Have your child show 11-3 using a number line. Have him or her explain how they are using the number line as they subtract.

Answer:

Explanation:

I used number line to subtract

Start at 11

Count back 3

10, 9, 8

So, 11 – 3 = 8.