Lesson objective: Multiply factors in a different order while keeping the same product.

This lesson helps to build procedural skill with the commutative property. Arrays are used here because they highlight the idea that the total stays the same when the factors are switched. This work develops students' understanding that a given set of factors has the same product, regardless of the order in which the factors are written.

Students engage in Mathematical Practice 7 (Look for and make use of structure) as they build or draw arrays and write equations while changing the order of factors to prove that it is always true that the product will remain the same.

**Key vocabulary:**

- arrays
- equation
- multiplication

**Special materials needed:**