# Lesson 6 Use Strategies and Algorithms to Add

Let’s consider when to use algorithms and when to use other strategies to add.

## Warm-up Number Talk: Little More, Little Less

Find the value of each expression mentally.

## Activity 1 Just Ones

Two methods of recording the addition of

Method 1

Method 2

## Problem 1

How is the newly composed ten and hundred recorded differently in each method?

## Problem 2

Try the second method of recording to add these numbers:

## Activity 2 How Would You Add?

Use a strategy of your choice to find the value of each sum. Show your reasoning. Organize it so it can be followed by others.

## Practice Problem

## Problem 1

What do the 1s above the 2 and 5 in 253 mean in this calculation?

Use an algorithm or another strategy to find the value of each sum.