Lesson objective: Divide to find equal groups or shares.

This lesson helps to build fluency with whole number division. Arrays are used here because they support using structure and organization to make equal groups. This work develops students' understanding that quotients are equal groups or shares.

Students engage in Mathematical Practice 1 (Make sense of problems and persevere in solving them) as they practice dividing and sharing manipulatives into different equal groups or rows. Using doubling and halving, breaking apart numbers, and skip counting, they will be able to explore easily with whole numbers.

Students engage in Mathematical Practice 7 (Look for and make use of structure) as they form distinguishable groups, rows, or jumps to distribute whole numbers into parts, shares or groups in many different combinations. They should be aware of equal groups and make use of structure by keeping the rows or groups equal. Using manipulatives, they can rearrange whole numbers into multiple equal groups to find possibilities. Recounting or double checking their groups or rows after they are finished sharing will help them be efficient in finding the answers. Questions such as "Are all of your rows equal?" or "How could your rearrange those to make them equal?" or "Do you have any clues right away that tell whether you can make equal groups or not?" will help students make better sense of the structures they are forming.

**Key vocabulary:**

- array
- equal groups
- divide
- quotient
- share
- unknown factor

**Special materials needed:**

- base ten blocks to help break numbers apart
- manipulatives such as square tiles, counters or cubes