Lesson 20
How Much in the Group? (optional)
Lesson Purpose
The purpose of this lesson is for students to solve fraction division problems that ask: “How many in one group?”
Lesson Narrative
In this optional lesson, students solve problems where a whole number quantity is a unit fraction of an unknown whole number. In these situations students may rely on their understanding of the relationship between multiplication and division. For example, if 8 ounces is \(\frac{1}{4}\) of the amount of water in a bottle, students might represent this with a tape diagram:
The tape diagram suggests the equation \(8 = \frac{1}{4} \times {?}\) which students will likely solve by seeing that \({?} = 4 \times 8\). The equation \(8 = \frac{1}{4} \times {?}\) can also be written using division with the equation \({?} \div 4 = 8\).
- Engagement
- MLR8
Learning Goals
Teacher Facing
- Represent and solve problems involving division of a whole number by a unit fraction.
Student Facing
- Let’s solve more problems involving multiplication and division with fractions.
Required Preparation
CCSS Standards
Addressing
Lesson Timeline
| Warm-up | 10 min |
| Activity 1 | 20 min |
| Activity 2 | 10 min |
| Activity 3 | 10 min |
| Lesson Synthesis | 10 min |
| Cool-down | 5 min |
Teacher Reflection Questions
What do you love most about math? How are you sharing that joy with your students and encouraging them to think about what they love about math?
Suggested Centers
- How Close? (1–5), Stage 6: Multiply to 3,000 (Addressing)
- Rolling for Fractions (3–5), Stage 5: Divide Unit Fractions and Whole Numbers (Addressing)