# Lesson 7 Does it Make a New Ten?

• Let’s add one-digit and two-digit numbers and write equations.

## Warm-up Which One Doesn’t Belong: Expressions

Which one doesn’t belong?

## Problem 1

Jada likes to look for ways to make a new ten when she adds.
Would she be able to a make a new ten when she adds to find the value of this sum?

1. If Jada could make a new ten, circle “Yes.”
If Jada could not make a new ten, circle “No.”

1. Yes

2. No

2. Explain how you know.
Find the value.
Write equations to show how you found the value of the sum.

## Problem 2

Jada likes to look for ways to make a new ten when she adds.
Would she be able to a make a new ten when she adds to find the value of this sum?
Does the expression make a new ten?

1. If Jada could make a new ten, circle “Yes.”
If Jada could not make a new ten, circle “No.”

1. Yes

2. No

2. Explain how you know.
Find the value.
Write equations to show how you found the value of the sum.

## Problem 3

Jada likes to look for ways to make a new ten when she adds.
Would she be able to a make a new ten when she adds to find the value of this sum?
Does the expression make a new ten?

1. If Jada could make a new ten, circle “Yes.”
If Jada could not make a new ten, circle “No.”

1. Yes

2. No

2. Explain how you know.
Find the value.
Write equations to show how you found the value of the sum.

## Problem 4

Jada likes to look for ways to make a new ten when she adds.
Would she be able to a make a new ten when she adds to find the value of this sum?
Does the expression make a new ten?

1. If Jada could make a new ten, circle “Yes.”
If Jada could not make a new ten, circle “No.”

1. Yes

2. No

2. Explain how you know.
Find the value.
Write equations to show how you found the value of the sum.

## Activity 2 Missing Numbers

Lin’s brother spilled water on her math work!
Figure out what number Lin wrote before it got smudged.

1. Lin wrote a one-digit number with which you can make a new ten when you find the value of the sum.

What could Lin’s number be?
Write equations to show your thinking.

2. Lin wrote a one-digit number with which you can not make a new ten when you find the value of the sum.

What could Lin’s number be?
Write equations to show your thinking.

3. Lin wrote a two-digit number with which you can make a new ten when you find the value of the sum.

What could Lin’s number be?
Write equations to show your thinking.

4. Lin wrote a two-digit number with which you can not make a new ten when you find the value of the sum.

What could Lin’s number be?
Write equations to show your thinking.

5. How do you know whether or not you can make a new ten when you are finding the value of a sum?

## Problem 1

Find the value of each sum.
Show your thinking using drawings, numbers, or words.

1. How are the problems the same?
How are they different?