# Lesson 8

Sumemos y restemos fracciones

### Lesson Purpose

The purpose of this lesson is for students to add fractions with unlike denominators in a way that makes sense to them.

### Lesson Narrative

In this lesson, students add and subtract fractions in a way that makes sense to them. They consider several important cases:

- The denominators of the two fractions are the same, which is review of work from a previous grade.
- One denominator is a multiple of the other so the fractions can be added by replacing only one of the fractions with an equivalent fraction.
- Neither denominator is a multiple of the other so a third new common denominator is needed to add the fractions.

- Action and Expression

- MLR8

Activity 2: Sumemos y restemos

### Learning Goals

Teacher Facing

- Add and subtract fractions with unlike denominators in a way that makes sense to them.

### Student Facing

- Sumemos y restemos fracciones.

### Required Materials

Materials to Copy

- Fraction Add and Subtract Sort

### Required Preparation

Activity 1:

- 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 | 15 min |

Activity 2 | 20 min |

Lesson Synthesis | 10 min |

Cool-down | 5 min |

### Teacher Reflection Questions

Which students had opportunities to share their diagrams and thinking during whole-class discussion? How did you select these students?

### Suggested Centers

- Would You Rather? (2–5), Stage 3: Compare Units in a Given System (Addressing)
- Compare (1–5), Stage 6: Add and Subtract Fractions (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 |