# Lesson 14 Towers of 10

Let’s figure out how many cubes are hidden.

## Warm-up What Do You Know About …?

What do you know about 10?

## Activity 1 Introduce What’s Behind My Back?, 10 Cubes

We are going to learn a new way to play the What’s Behind My Back? center.

## Activity 2 How Many Cubes Are Hidden?

Han had a tower of 10 cubes.

He snapped it into 2 parts and hid 1 part behind his back.

He showed his partner 4 cubes.

How many cubes is Han hiding behind his back?

## Activity 3 Centers: Choice Time

Choose a center.

What’s Behind My Back?

Math Fingers

Shake and Spill

Counting Collections

Roll and Add

## Practice Problem

## Problem 1

Mai has a tower of 10 connecting cubes.

She snaps the tower into 2 parts and puts one part behind her back.

She shows her partner 3 cubes.

How many cubes is Mai hiding?

Show your thinking using drawings, numbers, words, or objects.