Lesson objective: Design arrays.

This lesson helps to build the procedural skill of designing arrays for a given number of objects. Designing arrays is used here because it requires students to design arrays with an equal number of objects in each row and column. This work develops students' understanding that a** **group of objects can be organized in an array and thought of as a number of equal groups.

Students engage in Mathematical Practice 7 (Look for and make use of structure).** **As students compose arrays, they recognize that the array structure is a collection of rows or columns and that can be seen as a group of objects as they create arrays.

**Key vocabulary:**

- arrange
- array
- column
- equal
- group
- objects
- row