Lesson objective: Fluently solve multiplication and division problems to 100.

This lesson helps to build fluency with whole number multiplication and division to 100. Equations with unknowns are used here because it supports using multiplication and division as inverse operations. This work develops students' understanding that you can use the relationship between multiplication and division to multiply and divide within 100.

Students engage in Mathematical Practice 8 (Look for and express regularity in repeated reasoning) as they notice repetitive actions in computation when solving problems. For example, students can use skip counting or repeated addition or subtraction to solve a multiplication or division problem.

**Key vocabulary:**

- division
- inverse opeations
- multiplication
- relationship
- unknown quantity