The mathematical purpose of this lesson is for students to recall how verbal descriptions, tables, graphs, and equations are different representations of the same relationship. Students connect an equation to a graph or table of values in the context of linear relationships. They interpret a graph to answer questions about a context. They focus on the meaning of the numbers and in a linear equation of the form . Then, to preview the work in the Algebra 1 lesson, students encounter a model characterized by exponential decay. This lesson parallels the work in the associated Algebra 1 lesson: students revisit linear relationships in this lesson, while students encounter exponential relationships in the Algebra 1 lesson. When students explain how a graph or expression representing a model relates to the situation it represents, they are reasoning abstractly and quantitatively (MP2).

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