Lesson objective: Extend understanding that the order of two factors can be switched while still having the same product.

Students bring prior knowledge of multiplication from 3.OA.7. and 3.OA.A.3. This prior knowledge is extended to the commutative property as students explore what happens to an array when the factors are switched. A conceptual challenge students may encounter is thinking that this concept can be applied to division.

The concept is developed through work with arrays, which can be turned to show that the number of items remain the same.

This work helps students deepen their understanding of operations because students multiply two factors in different ways.

Students engage in Mathematical Practice 7** **(Look for and make use of structure) as they use arrays to represent how two factors can be switched while keeping the same product.

**Key vocabulary:**

- arrays
- equation
- factor
- multiplication
- number line
- product

**Special materials needed:**

- objects (such as square tiles) to create arrays (if needed)
- paper
- pencil