Lesson objective: Find factors of a whole number using area models or a t-chart.

This lesson helps to build procedural skill with finding factors of whole numbers. Area models are used here because it supports students' knowledge of multiplication representation from third grade. A t-chart is used here because it develops fluency in determining factors. This work develops students' understanding that a whole number is a multiple of its factors.

Students engage in Mathematical Practice 7 (look for and make use of structure) as they begin to notice the pattern of multiples and the relationship between factors and multiples.

**Key vocabulary:**

- area model
- factors
- multiples
- t-chart