Lesson 19

The purpose of this lesson is for students to interpret and solve problems that involve adding, subtracting, and multiplying fractions.

This optional lesson gives students additional opportunities to integrate and apply the work from this unit to solve novel contextual problems. All three activities prompt students to make sense of and persevere in solving problems that involve adding, subtracting, and multiplying fractions. In the first two activities, students think abstractly and quantitatively to relate their calculations to a situation (MP2). The last activity encourages students to identify structure in expressions with many different operations involving fractions (MP7).

Completing all three activities will take more than 60 minutes. Consider expanding the lesson across 2 days or selecting one or two activities based on students' needs or interests and time constraints.

• Each group needs 12 small sticky notes measuring 1\(\frac{7}{8}\) by 1\(\frac{3}{8}\) inches.

• Create one set of Match Cards for each group of 24 students.

What evidence did you see of students thinking flexibly and choosing a method strategically as they worked to solve problems? For students who chose a fixed way of reasoning about fractional amounts, what questions could you ask to prompt them to be more strategic?