Unit 6, Lesson 18
Subtraction in Equivalent Expressions
Grade 7
Preparation
Lesson Narrative
In this lesson, students begin working with equivalent expressions that involve negative numbers. They apply what they have learned about rewriting subtraction as adding the opposite. This enables students to apply properties of addition to generate equivalent expressions. For example, can be rewritten as and then rearranged as using the commutative property of addition. Then students use a similar strategy to make sense of the distributive property of multiplication over subtraction. As students rewrite an expression in different ways, they make use of structure (MP7).
- Explain (orally, in writing, and using other representations) how the distributive and commutative properties apply to expressions with negative coefficients.
- Justify (orally and in writing) whether expressions are equivalent, including rewriting subtraction as adding the opposite.
Let's find ways to work with subtraction in expressions.
Required Preparation
None