Lesson objective: Decompose the numbers 11 to 19 by finding the sum of 10 ones and 1-9 ones.

This lesson helps to build fluency with decomposing teen numbers. Number bonds are used here because it supports the idea of decomposing teen numbers into ten ones and some more ones. This work develops students' understanding that the numbers 11-19 are the sum of 10 ones and 1, 2, 3, 4, 5, 6, 7, 8, or 9 ones.

Students engage in Mathematical Practice 4 Model with mathmatics as they match numerals to pictutres and model what they see in a number bond.

**Key vocabulary:**

- add
- compose
- decompose
- equality
- equation
- number bond
- sum

**Special materials needed:**

- counters (optional)
- numeral/dot cards
- recording sheet
- ten frames (optional)