# Lesson 8 Different Ways to Decompose

Let’s compare different ways to subtract.

## Warm-up Number Talk: Multiples of 10

Find the value of each expression mentally.

## Activity 1 Aren’t You Missing Something?

Lin and Clare made base-ten diagrams to find the value of

Lin

Clare

What do you notice about their work? What do you wonder?

Lin and Clare each wrote equations to show their thinking. Explain how you know which group of equations matches Lin’s work and which matches Clare’s work.

A:

B:

How are Lin and Clare’s methods the same? How are they different?

## Activity 2 Different Ways to Decompose

## Problem 1

Andre found the value of

Do you think Andre’s method is more like Clare’s or Lin’s method? Explain.

## Problem 2

Find the value of each difference. Show your thinking.

## Practice Problem

## Problem 1

Here is how Clare found the value of

Here is how Han found the value of

How are Han’s and Clare’s calculations the same?

How are they different?