Lesson objective: Fluently write expressions and use substitution to solve real-world mathematical problems.

This lesson helps to build fluency with writing algebraic expressions. A table is used here because it supports the previous ratio and unit rate work students have done in previous units. This work develops students' understanding that mathematical relationships can be represented with expressions, and we can use those expressions as we use numbers.

Students engage in Mathematical Practice 1 (Make sense of problems and persevere in solving them) as they read a situation, use or create a table to represent the situation with an expression, and use substitution to evaluate the expression.

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