The goal of this lesson is for students to understand why we can generally approach solving by subtracting the same value from each side and why we can generally approach solving by dividing each side by the same value. This understanding is accomplished by considering what can be done to a hanger to keep it balanced.

Previously, students solved a variable equation by thinking about values for the variable that made the equation true. Here, they use the image of a balanced hanger to reason about things they could “do” to the equation to make the solution easier to see while still keeping both sides of the equation equal (balanced). In the next lesson, students will apply this strategy to solve equations algebraically.