# Lesson 2 Keep Track of Objects

Let’s figure out how many objects are in our collections.

## Warm-up Number Talk: Add and Subtract 0 and 1

Find the value of each expression.

## Activity 1 Counting Collections

How many objects are in your collection?

## Activity 2 Different Ways to Keep Track

Choose either the 10-frame or the counting mat to help you figure out how many objects are in your collection.

## Activity 3 Centers: Choice Time

Choose a center.

Number Race

Subtraction Towers

5-frames