We included **HMH Into Math Grade 2 Answer Key PDF** **Module 10 Lesson 2 Use a Number Line **to make students experts in learning maths.

## HMH Into Math Grade 2 Module 10 Lesson 2 Answer Key Use a Number Line

I Can add or subtract by counting on or counting back on a number line.

**Spark Your Learning**

Find the answer to Deja’s riddle.

Number: ___40______

Deja is solving a riddle. Deja’s riddle says: I am a number that is 1 ten and 6 ones more than 24. What number am I? Use the number line to find the answer to Deja’s riddle.

Answer:

The number is 40,

Explanation:

Given Deja is solving a riddle.

Deja’s riddle says: I am a number that is 1 ten and

6 ones more than 24 using the number line moving 1 ten

and 6 ones counting on we get 40, therefore the number is 40.

**Build Understanding**

Question 1.

Jasmine scored 82 on her first spelling test. On her second spelling test, Jasmine scored 15 points more than on her first test. What did Jasmine score on her second spelling test? Use the tools below to solve.

A. Show Jasmine’s first test score in the chart and on the number line.

Answer:

Explanation:

Given Jasmine scored 82 on her first spelling test,

Shown Jasmine’s first test score in the chart and

on the number line above.

B. How many more points did Jasmine score on her second test?

__15__ points

Answer:

15 points,

Explanation:

On her second spelling test, Jasmine scored 15 points

more than on her first test.

C. Show how to add in the chart and on the number line.

Answer:

Explanation:

In the chart circled 82 and counted forwared 15 numbers

and added, On number line starting from 82 moved

15 numbers forward reached 97 as shown above.

D. Solve. Complete the equation to show what Jasmine scored on her second spelling test.

__82__ + __15_____ = ___97_____

Answer:

82 + 15 = 97, Jasmine scored 97 on her

second spelling test,

Explanation:

Given Jasmine scored 82 on her first spelling test.

On her second spelling test, Jasmine scored 15 points

more than on her first test. So Jasmine score on her

second spelling test is 82 + 15 = 97, therefore

Jasmine scored 97 on her second spelling test.

**Turn and Talk** How does thinking of 15 as 1 ten 5 ones

help you solve the problem?

Answer:

It made counting easy,

Explanation:

Instead of counting continuosly 15 thought of

15 as 1 ten and 5 ones which made counting easy.

Question 2.

There are 36 ducks swimming in the pond. 24 ducks fly away.

Now how many ducks are swimming in the pond?

You can show this problem on an open number line.

This open number line does not have tick marks.

It only shows the number you start with.

A. How many ducks are swimming in the pond?

Find the number on the number line.

Answer:

Explanation:

Given there are 36 ducks swimming in the pond,

Found the number on the number line above.

B. How many ducks fly away?

___24____ ducks

Answer:

24 ducks fly away,

Explanation:

Given there are 36 ducks swimming in the pond.

24 ducks fly away.

C. Count back by tens and ones to show how many ducks fly away.

Show your work on the number line.

Answer:

Explanation:

Counted back 24 from 36 shown on the number line.

D. Solve,

____12____ ducks swimming now

Answer:

36 -24 = 12,

Explanation:

Solved given 36 ducks swimming in the pond.

24 ducks fly away, the equation as 36 – 24 =12,

therefore 12 ducks are swimming now.

**Turn and Talk** How is working with an open number line helpful?

Answer:

Directly helpful,

Explanation:

In an open number line we directly point the given

values and solve not by counting forward or backward.

**Check Understanding**

Use a number line. Solve.

Question 1.

There are 47 pencils in a box. 13 children each take a pencil. How many pencils are still in the box?

__34______ pencils

Answer:

There are 34 pencils still in the box,

Explanation:

Given there are 47 pencils in a box.

13 children each take a pencil.

Number of pencils are still in the box by using

number line starting from 47 and moving back

13 we are at 34 means still there are 34 pencils

still in the box.

Question 2.

John has 31 marbles. He finds 17 more marbles.

How many marbles does John have now?

___48_____ marbles

Answer:

Explanation:

Given John has 31 marbles. He finds 17 more marbles,

So on number line we start at 31 and count forward 17

we get 48 so there are 31 + 17 = 48 marbles.

**On Your Own**

Question 3.

Use Structure There are 13 second graders and 14 third graders in an art club. How many children are ¡n the club? Use tens and ones to solve. Show your work.

___27_____ children

Answer:

Explanation:

Given there are 13 second graders and 14

third graders in an art club. Using number line started

with 13 and counting on 14 reached 27, therefore

there are 27 children in the club.

**Solve.**

Question 4.

73 + 15 = ___88_____

Answer:

Explanation:

Given to solve 73 + 15 first we start from 73

on number line and counting on 15 move forward

we get 88.

Question 5.

49 – 11 = __38___

Answer:

Explanation:

Given to solve 49 -11 first we start from 49

on number line and counting back 11 move back

we get 38.

**I’m in a Learning Mindset!**

What helps me finish my work?

Answer:

Chart and number line,

Explanation:

Counting on and back on the chart and number line

helped me to finish my work.