Lesson objective: Add on to make 10.

This lesson helps to build procedural skill with finding the number that makes 10 when added to a given number one through nine. 10 two-sided counters are used here because they helps students track the total of 10 objects while also tracking how many objects they are counting on. This work develops students' understanding that for any number one to nine, there is one number we can add to it to get 10.

Students engage in Mathematical Practice 7 (Look for and make use of structure) as they notice that there is only one number that is added to each number one to nine that will make 10. The ability to make 10 is also foundational to place value understanding.

**Key vocabulary:**

- compose
- count on
- decompose
- make a 10

**Special materials needed:**

- 10-strips or 10-frames
- two-sided counters (commercial or painted lima beans)
- Counter Toss recording sheet