Lesson objective: Understand that the array model for multiplication can be used to find a dividend, divisor, or quotient in a division problem.

Students bring prior knowledge of the array model for multiplication from 4.NBT.B.5. This prior knowledge is extended to division as students use the array model to solve division problems. A conceptual challenge students may encounter is understanding that there is an inverse relationship between multiplication and division.

The concept is developed through work with array models, which are used to solve division problems.

This work helps students deepen their understanding of operations because students explore the inverse relationship between multiplication and division.

Students engage in Mathematical Practice 8 (Look for and express regularity) in repeated reasoning as they set up an array to solve problems. The students will start with the dividend and divisor and will be required to find the quotient.

**Key vocabulary:**

- array
- dividend
- divisor
- quotient

**Special materials needed:**

- base ten blocks (optional)