# Lesson 15 Explain How You Counted

Let’s count collections of objects and tell our partners how we counted.

## Warm-up Questions About Us: Represent Attendance

How many of us are here today?

## Activity 1 Counting Collections: Share How You Counted

Figure out how many objects are in your collection.

Switch collections with a partner. Figure out how many objects are in your new collection.

Tell your partner how many objects are in your collection. Show them how you counted the objects.

## Activity 2 Use a Counting Mat to Keep Track

Use the counting mat to figure out how many objects are in your collection.

## Activity 3 Centers: Choice Time

Choose a center.

Geoblocks

Connecting Cubes

Pattern Blocks

Picture Books