This Instructional Activity is a part of the Lesson 6, Unit 6, Grade 7. The goal of this activity is for students to notice the structure of equations. Any way of sorting is fine, but the discussion should land on explaining how equations involving an expression like p(x+q) are different from ones that have an expression like px+q. Monitor for different ways groups choose to categorize the equations, but especially for categories that distinguish between these two types of expressions. As students work, encourage them to refine their descriptions of equations using more precise language and mathematical terms.