Lesson Objective: Apply knowledge of unit rates and use multiple number lines to compare the costs across three items.

Students are typically asked to work with two rates. In this application problem, students compare three pairs of quantities that vary in different ways. Understanding how the parallel number lines show the relationships precedes understanding how the relationships will be shown with equations and graphs in Unit 2.

Key Concept students will use:

Skills students will use:

Students engage in Mathematical Practices 1 and 3. They must make sense of the problem, recognizing that the most obvious-seeming answer is not necessarily correct. They also must construct a viable argument for why Tiny-Tarts are the most cost-effective candy to buy.

Key vocabulary: