## Let's Count to 20

In this unit, students make groups of 10 to 20 objects, connect number names to the groups, compose and decompose numbers, and use numerals to record the size of a group. Visual, auditory, and kinesthetic activities are included in each lesson. This unit is most appropriate for students typically in the first grade.

**Math
Content**

Students will:

- Understand the concept of number.
- Build relationships between numbers.
- Become familiar with equality.
- Begin writing numerals.

### Building Numbers Up to 10

Pre-K-2

Students construct sets of numbers up to 10, write the numerals up to 10, and count up to 10 rationally. They use ten frames and also make bean sticks. ### Building Sets of 11 and 12

Pre-K-2

Students use bean sticks, connecting cubes, and ten frames to construct sets of 11 and 12, record them, and compare them.### Building Sets of 13 and 14

Pre-K-2

Students construct and identify sets of size 13 and size 14. They compare sets to sets of size 13 and size 14, and record the number in the sets. They decompose a set of 13 and a set of 14 in several ways. ### Building Sets of 15 and 16

Pre-K-2

Students explore the numbers 15 and 16. They make and decompose sets of size 15 and size 16, write the numerals 15 and 16, and compare other sets to sets of size 15 and size 16.### Building Sets of 17 and 18

Pre-K-2

Students construct sets up to size 18, write the numerals 17 and 18, and model 17 and 18 with bean sticks, cubes, and ten frames.### Building Sets of 19 and 20

Pre-K-2

Students explore sets of 19 and 20. They count up to 20, construct and decompose sets up to 20, and record the decomposition.