# Lesson 23 Use a Ten to Subtract

Let’s use 10 to help us subtract.

## Warm-up Number Talk: Subtract to Make 10

Find the value of each expression mentally.

## Activity 1 Number Card Subtraction with 10-frames

Choose a teen number card.

Build the number on 10-frames.

Choose a number card to subtract.

Find the difference.

Write an equation.

My equations:

Pick your favorite equation.

Show how you found the value of the difference using drawings, numbers, or words.

## Activity 2 Diego and Andre Find the Difference

Diego is playing Number Card Subtraction.

He started with 15 and then picked an 8.

He started out by doing this:

What could Diego do next to find the difference?

Andre was also finding the value of

He started out by doing this:

What could Andre do next to find the difference?

Find the value of each difference using Diego’s way or Andre’s way.

Show your thinking using drawings, numbers, or words.

Show your thinking using drawings, numbers, or words.

## Practice Problem

## Problem 1

Find the value of each difference.

Show your thinking using drawings, numbers, or words.