Lesson objective: Find numbers or expressions to create equivalent expressions.

This lesson helps to build procedural skill with finding numbers or expressions that have a given value. Balance scales are used here because they support student understanding of balance and equality. This work develops students' understanding that the equals sign means that the expressions on either side have the same value.

Students engage in Mathematical Practice 2 (reason abstractly and quantitatively)** **as they use the balance scales to create equivalent expressions.

**Key vocabulary:**

- balance
- equal
- equation
- expression
- value

**Special materials needed:**

- balance scales (per pair or group)
- counters