# Lesson 12 Decompose to Subtract

• Let’s subtract within 1,000.

## Warm-up What Do You Know About …?

What do you know about 354?

How could we represent the number 354?

## Activity 1 Subtract from 354

Find the value of each expression in any way that makes sense to you. Explain or show your reasoning.

## Activity 2 Decompose With Base-ten Blocks

Work with your partner to find the value of each expression.

• Partner A: Read the expression and represent the larger number using blocks.

• Partner B: Decide if you will decompose a ten and explain. Then subtract.

• Discuss and write the difference.

• Switch roles.

## Problem 1

1. Find the value of each difference.

2. Jada drew this picture to find the value of a difference. What difference did Jada calculate? Explain how you know.