Lesson objective: Find unknowns in different types of multiplicative comparison problems.

This lesson helps to build procedural skill with multiplicative comparisons. Tape diagrams are used here because they support conceptualizing a larger amount and a smaller amount and how the smaller amount is repeatedly added a certain number of times to build the greater amount. This work develops students' understanding that the meaning of the multiplicative relationship does not change depending on the type of problem being solved.

Students engage in Mathematical Practice 4 (model with mathematics) as they show how one quantity is a certain number of times larger than the other quantity and solve for the unknown in different types of problems.

**Key vocabulary:**

- comparison
- equation
- factor
- greater than
- less than
- product
- tape diagram
- times
- unknown

**Special materials needed:**

- colored pencils, if desired, for coloring in tape diagrams
- graph paper, if desired, for creating tape diagrams