# Lesson 19

Flexible with Fractions (optional)

### Lesson Purpose

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

### Lesson Narrative

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.

• Representation

### Learning Goals

Teacher Facing

• Interpret and solve problems that involve the addition, subtraction, and multiplication of fractions.

### Student Facing

• Let’s solve all kinds of problems involving fractions.

### Required Materials

Materials to Gather

Materials to Copy

• Find a Match

### Required Preparation

Activity 1:

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

Activity 3:

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

Building Towards

### Lesson Timeline

 Warm-up 10 min Activity 1 25 min Activity 2 20 min Activity 3 25 min Lesson Synthesis 5 min Cool-down 5 min

### Teacher Reflection Questions

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?