Lesson 8
Add and Subtract Fractions
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: Add and Subtract
Learning Goals
Teacher Facing
- Add and subtract fractions with unlike denominators in a way that makes sense to them.
Student Facing
- Let’s add and subtract fractions.
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 |