Lesson objective: Apply their knowledge that the numbers 11-19 are the sum of 10 ones and 1, 2, 3, 4, 5, 6, 7, 8, or 9 ones.

This lesson provides an opportunity for students to apply their knowledge and understanding of numbers 11-19 to a mathematical situation. Students are asked to represent the numbers 11-19 in various representations which include: pictures, number bonds, and equations.

Key Concept students will use:

- The numbers 11-19 are the sum of 10 ones and 1, 2, 3, 4, 5, 6, 7, 8, or 9 ones.

Skills students will use:

- their knowledge that numbers 11-19 are composed of ten ones and one, two, three, four, five, six, seven, eight, or nine ones.
- the concept that the concept that the numbers 11-19 are the sum of ten ones and some more ones.

Students engage in Mathematical Practice 7** s**tudents** **look for and make use of structure as they represent teen numbers in various ways.

**Key vocabulary: **

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

**Special materials needed:**

- counters (optional)
- My Teen Numbers book template
- ten frames (optional)