**Lesson objective:** Write related multiplication and division equations with unknowns.

This lesson helps to build fluency with writing related multiplication and division equations with variables. The area model is used here because it illustrates what the three numbers represent in multiplication and division equations. This work develops students' understanding that we can use the relationship between the three whole numbers in a multiplication and division equation to identify a missing number that makes the equation true.

Students engage in Mathematical Practice 6** **(attend to precision) as they write equivalent equations and draw clear and accurate models to represent multiplication and division equations.

**Key vocabulary:**

- division equation
- fact family
- model
- multiplication equation
- related
- row
- unknown

**Special materials needed:**

- grid paper
- square tiles