In grade 6, students worked extensively with the distributive property involving both addition and subtraction, but only with positive coefficients. In the previous lesson, students learned to rewrite subtraction as "adding the opposite" to avoid common pitfalls. In this lesson, students practice using the distributive property to write equivalent expressions when there are rational coefficients. Some of the expressions they will work with are in preparation for understanding combining like terms in terms of the distributive property, coming up in the next lesson. (For example, \(17a−13a\) can be rewritten \(a(17−13)\) using the distributive property, so it is equivalent to \(a⋅4\) or \(4a\).
Lesson overview
 19.1 Warmup: Number Talk: Parentheses (10 minutes)

19.2 Activity: Factoring and Expanding with Negative Numbers (20 minutes)
 Includes "Are you Ready for More?" extension problem
 Lesson Synthesis
 19.3 Cooldown: Equivalent Expressions (5 minutes)
Learning goals:
 Apply the distributive property to expand or factor an expression that includes negative coefficients, and explain (orally and using other representations) the reasoning.
 Comprehend the terms “expand” and “factor” (in spoken and written language) in relation to the distributive property.
Learning goals (student facing):
 Let's use the distributive property to write expressions in different ways.
Learning targets (student facing):
 I can organize my work when I use the distributive property.
 I can use the distributive property to rewrite expressions with positive and negative numbers.
 I understand that factoring and expanding are words used to describe using the distributive property to write equivalent expressions.
Glossary:
 expand  To expand an expression, we use the distributive property to rewrite a product as a sum. The new expression is equivalent to the original expression. For example, we can expand the expression \(5(4x+7)\) to get the equivalent expression \(20x+35\).
 factor (an expression)  To factor an expression, we use the distributive property to rewrite a sum as a product. The new expression is equivalent to the original expression. For example, we can factor the expression \(20x+35\) to get the equivalent expression \(5(4x+7)\).
 Access the complete Grade 7 glossary.
Standards:
 This lesson builds on the standard:CCSS.7.NS.AMO.7.NS.A
 This lesson builds towards the standard:CCSS.7.EE.A.1MS.7.EE.1MO.7.EEI.A.1
IM 6–8 Math was originally developed by Open Up Resources and authored by Illustrative Mathematics, and is copyright 20172019 by Open Up Resources. It is licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0). OUR's 6–8 Math Curriculum is available at https://openupresources.org/mathcurriculum/.
Adaptations and updates to IM 6–8 Math are copyright 2019 by Illustrative Mathematics, and are licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0).
Adaptations to add additional English language learner supports are copyright 2019 by Open Up Resources, and are licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0).
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