Lesson objective: Add a two-digit number with a one-digit number, sometimes composing a ten.

This lesson helps to build fluency with composing a new ten. Cubes are used here because students will be able to see that a new ten is "complete." This work develops students' understanding that when adding a two-digit number with a one-digit number, sometimes it is neccessary to compose a new ten.

Students engage in Mathematical Practice 1 (Make Sense of Problems and Perservere in Solving Them) as they determine whether or not a new ten needs to be made while playing the game.

**Key vocabulary:**

- compose
- decompose
- ones
- tens

**Special materials needed:**

- 10-sided dice (see additional materials for template)
- Recording Sheet