# Lesson 12

Solve Problems

### Lesson Purpose

The purpose of this lesson is for students to solve problems that involve adding and subtracting fractions with unlike denominators.

### Lesson Narrative

In this lesson, students apply their understanding of fraction addition and subtraction to solve multi-step problems. They work with fractions and mixed numbers and make estimates as well as finding the value of sums and differences. Students find the sums and differences in a way that makes sense to them. They will choose common denominators and can also use techniques they have seen in earlier lessons such as adding on to make a whole number.
• Representation
• MLR6

### Learning Goals

Teacher Facing

• Solve problems involving addition and subtraction of fractions with unlike denominators.

### Student Facing

• Let’s solve more problems by adding and subtracting fractions with unlike denominators.

### Lesson Timeline

 Warm-up 10 min Activity 1 20 min Activity 2 15 min Lesson Synthesis 10 min Cool-down 5 min

### Teacher Reflection Questions

What strategies did most students use to add and subtract fractions today? What strategies did you anticipate? Which did you not anticipate?

### Suggested Centers

• How Close? (1–5), Stage 9: Add Fractions to 5 (Addressing)
• Creating Line Plots (2–5), Stage 3: Eighth Inches, Add and Subtract (Supporting)

### Print Formatted Materials

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