In this lesson, students interpret and generate equivalent numerical expressions using the distributive property. In previous grades, students used the distributive property informally to explain strategies as they developed multiplication fluency. They used rectangular diagrams to make sense of the distributive property and explain their reasoning, without naming the property.

The activities in this lesson are designed to elicit this understanding, from students’ work with computation and with rectangular diagrams, and to support students' abstract and quantitative reasoning as they use the distributive property as a way to generate and justify equivalent numerical expressions (MP2). The term “distributive property” is used formally with students, although students may continue to explain their understanding of the property using terms that make sense to them throughout the unit.