We included **HMH Into Math Grade 2 Answer Key PDF** **Module 20 Lesson 3 Relate Centimeters to a Number Line **to make students experts in learning maths.

## HMH Into Math Grade 2 Module 20 Lesson 3 Answer Key Relate Centimeters to a Number Line

I Can solve two-digit addition and subtraction problems using a centimeter ruler or a meter stick as a number line.

**Spark Your Learning**

Measure a folder. Is it large enough to fit a label that is 12 centimeters long?

Distribute a standard pocket folder to each pair. Tomas is labeling his school supplies with his name. He wants to put a name label on his folder. He needs to measure the length of his folder to make sure the label will fit. Find a way to measure the length of your folder to see if it is big enough to fit a label that is 12 centimeters long. Draw to show how you solved the problem.

Answer:

A ruler is used to measure the folder

**Build Understanding**

In school, Chantal learned how to solve problems on a number line. Today, she has some homework problems about centimeter length. so she made a number line to use. But something went wrong. How can Chantal fix her number line?

A. What do you notice about Chantal’s number line?

Answer:

The numbers are missing in the number line,

he didn’t wrote the numbers correctly.

And the length between the number are not equal.

B. What measuring tool could Chantal have used to help her make a correct number line?

Answer:

He can use a ruler or yardstick as a measuring tool.

By ruler he can measure correctly.

C. Use a centimeter ruler to make a number line Chantal can use.

Answer:

**Turn and Talk** Could you use the number line you made to measure an object? Explain.

Answer:

No, we cannot measure the object with number line,

That is measured with the help of a scale.

**Step It Out**

Question 1.

A watermelon is 18 centimeters long. Then it grows 16 more centimeters. How long is the watermelon now?

A. On the meter stick, mark the number that shows how long the watermelon is the first time it is measured.

Answer:

B. How many centimeters does the watermelon grow?

_________ centimeters = _________ ten ________ ones

Answer:

16 centimeters = 1 ten 6 ones

C. On the meter stick, count on by ones to add the ones. Then count on by ten to add the ten.

Answer:

D. Complete the equation to show how the watermelon grows.

__________ centimeters + ___________ centimeters = _________ centimeters

Answer:

18 centimeters + 16 centimeters = 34 centimeters

Explanation:

A watermelon is 18 centimeters long.

Then it grows 16 more centimeters.

18 + 16 = 34

34 centimeters long is the watermelon now

**Check Understanding**

Question 1.

Liam has a ribbon that is 26 centimeters long. Fiona has a ribbon that is 19 centimeters long. How much longer is Liam’s ribbon than Fiona’s ribbon? Use a centimeter ruler or meter stick to solve.

__________ centimeters

Answer:

7 centimeters

Explanation:

Liam has a ribbon that is 26 centimeters long.

Fiona has a ribbon that is 19 centimeters long.

26 – 19 = 7

7 centimeter longer is Liam’s ribbon than Fiona’s ribbon

**On Your Own**

**Use a centimeter ruler or meter stick to solve.**

Question 2.

**Construct Arguments** Mrs. Morgan has a wood board that is 67 centimeters long. She cuts off a piece of the board. The board is now 49 centimeters long. How many centimeters does Mrs. Morgan cut off?

___________ centimeters

Explain how you found your answer.

Answer:

Mrs. Morgan has a wood board that is 67 centimeters long.

She cuts off a piece of the board.

The board is now 49 centimeters long.

let n be the unknown length

n = 67 – 49

n = 18

Mrs. Morgan cut off 18 centimeters long wood.

Question 3.

**Reason** Samuel tapes paper strips together for a project. One sheet of paper is 30 centimeters long. The other sheet of paper is 14 centimeters long. When he tapes them together without gaps, how long will the paper strip be?

___________ centimeters

Answer:

44 centimeters

Explanation:

One sheet of paper is 30 centimeters long.

The other sheet of paper is 14 centimeters long.

let n be the unknown length

n = 30 + 14

n = 44

Question 4.

**Use Structure** Amber has a roll of stickers that is 75 centimeters long. She cuts off 27 centimeters of stickers from the roll to share with a friend. How many centimeters of stickers are on the roll now?

__________ centimeters

Answer:

48 centimeters

Explanation:

Amber has a roll of stickers that is 75 centimeters long.

then she cuts 27 centimeters of stickers .

let n be the unknown length

n = 75 – 27

n = 48

48 centimeters of stickers are on the roll now

**I’m in a Learning Mindset!**

What strategies do I have to solve problems about length?

Answer:

We have to frame a equation,

then we have to add or subtract according to the equation.