# Lesson 10 Subtraction Algorithms (Part 3)

Let’s learn another algorithm to subtract.

## Warm-up Notice and Wonder: Digits that Disappear

What do you notice? What do you wonder?

## Activity 1 A New Subtraction Algorithm

Andre and Clare found the value of

Andre’s algorithm

Clare’s algorithm

Complete both algorithms to find the difference.

Andre and Clare started their subtraction in different ways. How did their way of starting affect the steps needed to find the difference?

## Activity 2 Try Clare’s Algorithm

Clare used an algorithm to find the value of

Try using her algorithm to find the value of each difference.

## Practice Problem

## Problem 1

Use an algorithm of your choice to find the value of

. Use an algorithm of your choice to find the value of

.