The mathematical purpose of this lesson is to review algebraic moves that preserve equivalence of expressions, specifically the distributive, commutative, and associative properties. The work of this lesson connects to previous work done in grade 7, when students used properties of operations to generate equivalent expressions. This lesson prepares students for the work in the associated Algebra 1 lesson because they will recognize equivalent equations and explain why they share the same solution. Students have an opportunity to reason abstractly and quantitatively by applying their understanding of properties of operations on numbers to algebraic expressions (MP2).

Technology isn't required for this lesson, but there are opportunities for students to choose to use appropriate technology to solve problems. We recommend making technology available.