# Lesson 9

Differences of Fractions

### Lesson Purpose

### Lesson Narrative

Previously, students decomposed fractions into sums of other fractions and wrote equations to record the decompositions. They also used number lines to reason about addition of fractions with the same denominator. In this lesson, students use number lines to think about differences of fractions with the same denominator. They also practice reasoning about equivalence and decomposing fractions (including mixed numbers) mentally to facilitate subtraction.

As in earlier grades, students may think about subtracting as taking away a number from another number, or as finding an unknown addend. The way they represent differences of fractions on a number line may vary accordingly.

- Engagement

- MLR8

### Learning Goals

Teacher Facing

- Reason about subtraction of fractions with the same denominator using a number line.

### Student Facing

- Let’s explore differences of fractions on a number line.

### Required Materials

Materials to Copy

- Make a Jump, Subtraction Edition

### Required Preparation

Activity 3:

- Create a set of cards from the blackline master for each group of 2.

### CCSS Standards

Addressing

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 20 min |

Activity 2 | 15 min |

Activity 3 | 15 min |

Lesson Synthesis | 10 min |

Cool-down | 5 min |

### Teacher Reflection Questions

### Suggested Centers

- Rolling for Fractions (3–5), Stage 2: Multiply a Fraction by a Whole Number (Addressing)
- Estimate and Measure (1–4), Stage 3: Quarter Inches (Supporting)
- Target Measurements (2–5), Stage 2: Quarter Inches (Supporting)

### Print Formatted Materials

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Student Task Statements | docx | |

Lesson Cover Page | docx | |

Cool Down | Log In | |

Teacher Guide | Log In | |

Teacher Presentation Materials | docx | |

Blackline Masters | zip |