Lesson 4.1 - Addition Properties

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Lesson 4.2 - Writing Expressions

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Lesson 4.2 - Solving Expressions

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Lesson 4.3a - Expressions with Variables

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Lesson 4.3b - Solving Expressions with Variables

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Lesson 4.4 - Addition and Subtraction Equations

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Lesson 4.5 - Adding Equals to Equals

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Lesson 4.7 - Patterns:  Find a Rule