# Lesson 2 Explore Expressions and Sums

Let’s write addition expressions and find the sum of two numbers.

## Warm-up Choral Count: Count to 41

Count by 1, starting at 0.

What patterns do you see?

## Activity 1 Matching Dot Cards and Expressions

## Problem 1

Match each pair of dots to an expression. Then, find the total.

expression | total |
---|---|

## Problem 2

Draw the missing dots to match the expression. Then, find the total.

Expression:

Total:

Expression:

Total:

Expression:

Total:

## Problem 3

Write the missing expression to match the dots. Then, find the total.

Expression:

Total:

Expression:

Total:

## Activity 2 Introduce: Check it Off, Add within 10

Take turns choosing two cards, finding the sum, and writing an addition expression. You may have more than one expression for each sum.

## Practice Problems

## Problem 1

Circle the expression that matches the dots.

## Problem 2

Circle the dots that match the expression: