# Lesson 18 Patterns in Addition

Let’s look for and use patterns to help us add within 20.

## Warm-up How Many Do You See: More Double 10-frames

How many do you see?

How do you see them?

## Activity 1 Expression Match

Take out all the expression cards that have the number 10.

Mix up the rest of the cards.

Pick a card.

Place the card under the expression with 10 that it is equal to.

## Activity 2 Compare and Connect: Gallery Walk

Create a visual display that shows the expressions equal to the expression with 10 I assigned you.

## Activity 3 Centers: Choice Time

Choose a center.

Shake and Spill

Compare

Number Puzzles

## Practice Problem

## Problem 1

Select **3** expressions that have the same value as 10 + 3.