In this lesson, students represent and reason about contexts, using tape diagrams. Students may have had experience with tape diagrams in earlier grades, and have seen some examples of their use in prior units. For example, tape diagrams were used to represent percent increase and decrease situations in an earlier unit.

First, students interpret some given tape diagrams. Then they interpret a story and create tape diagrams. While the contexts lead to equations of the forms and , this lesson is not about writing equations. Likewise, students are asked to find an unknown value in several story problems, but the intention is for them to use any reasoning that makes sense to them. It is not expected that they write and solve equations, or that any particular method is stressed.