# Lesson 11

Divide Unit Fractions by Whole Numbers

### Lesson Purpose

The purpose of this lesson is for students to divide a unit fraction by a whole number.

### Lesson Narrative

The purpose of this lesson is for students to determine the size of the piece when a unit fraction is divided into equally sized parts. Students revisit the context of a pan of macaroni and cheese from earlier lessons when they multiplied unit fractions by unit fractions. The familiar context can help students make connections between multiplication and division. Students should be encouraged to solve the problems in a way that makes sense to them. The relationship between multiplication and division is meant to be exploratory. In later lessons, students will formalize this relationship.

- Representation

### Learning Goals

Teacher Facing

- Divide a unit fraction by a whole number, in context, in a way that makes sense to them.

### Student Facing

- Let’s divide a unit fraction by a whole number.

### Required Materials

Materials to Gather

### Required Preparation

### CCSS Standards

### 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

How did the student work you selected impact the direction of the discussion? What student work might you pick next time if you taught the lesson again?

### Suggested Centers

- Rolling for Fractions (3–5), Stage 4: Multiply Fractions (Addressing)
- Compare (1–5), Stage 4: Divide within 100 (Supporting)
- How Close? (1–5), Stage 7: Multiply Fractions and Whole Numbers to 5 (Supporting)