The mathematical purpose of this lesson is for students to review the meaning of exponents. Students practice using numbers with whole-number exponents to represent a situation and to create equivalent expressions. The work of this lesson connects to previous work done in grade 6 in which students learned to interpret expressions that use exponents. It also connects to work done in grade 8 in which students learned how to create equivalent expressions involving operations with exponents.

This lesson prepares students to understand contexts that can be characterized using exponents in the associated Algebra 1 lesson. When students write an expression in terms of after doing repeated numerical calculations, they express regularity in repeated reasoning (MP8). In the last activity, when students trade roles explaining their thinking and listening, they have opportunities to explain their reasoning and critique the reasoning of others (MP3).