# Lesson 18 Equations With Unknowns

Let’s make sense of equations with empty boxes.

## Warm-up Notice and Wonder: Equations With an Unknown

What do you notice?

What do you wonder?

## Activity 1 Match Stories and Equations

You have two sets of cards. One set of cards has the story problems we used in the last lesson. The other set of cards has equations with unknown values.

Work with your partner to match the story problems to the equations. One story has more than one equation. Be sure you can explain how you know they match.

## Activity 2 Which Equation?

9 students are playing bingo.

3 students are using blue chips to cover their boards.

The other students are using yellow chips.

How many students are using yellow chips?

Explain how each equation matches the story problem.

Show your thinking using drawings, numbers, or words.

Clare wrote

Jada wrote

## Practice Problem

## Problem 1

There were 7 apples in the basket.

Tyler added some more apples to the basket.

Now there are 9 apples in the basket.

How many apples did Tyler add to the basket?

Select 2 equations that match the story.