# Lesson 12

Represent Division of Unit Fractions by Whole Numbers

### Lesson Purpose

The purpose of this lesson is for students to use diagrams and equations to represent division of a unit fraction by a whole number.

### Lesson Narrative

In the previous lesson, students solved problems about dividing a unit fraction by a whole number in a way that made sense to them. In this lesson, students use tape diagrams to represent division of a unit fraction by a whole number. The tape diagrams used to represent the problems are familiar to students from earlier grades. Here is a tape diagram showing $$\frac{1}{4}$$, one out of 4 pieces is shaded:

One way to show $$\frac{1}{4} \div 3$$ is to divide the $$\frac{1}{4}$$ into 3 equal pieces.

To see how much is shaded we can divide all of the $$\frac{1}{4}$$s and see that $$\frac{1}{4} \div 3 = \frac{1}{12}$$.

Students use these diagrams to understand this series of steps representing division of a unit fraction by a whole number throughout the lesson.

• Engagement

Activity 2: Priya’s Work

### Learning Goals

Teacher Facing

• Make sense of diagrams that represent division of a unit fraction by a whole number.

### Student Facing

• Let’s make sense of diagrams that represent division of a unit fraction by a whole number.

### Lesson Timeline

 Warm-up 10 min Activity 1 10 min Activity 2 10 min Activity 3 15 min Lesson Synthesis 10 min Cool-down 5 min

### Teacher Reflection Questions

What did you say, do, or ask during the lesson synthesis that helped students be clear on the learning of the day? How did understanding the cool-down of the lesson before you started teaching today help you synthesize that learning?

### 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)

### Print Formatted Materials

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