This Instructional Activity is a part of the Lesson 2, Unit 6, Grade 6. In this activity, students see how an equation can represent a situation with an unknown amount. Students are presented with three stories. Each story involves the same three quantities: 5, 20, and an unknown amount x. Students think about the actions (running a number of miles, splitting up cups of cat food) and relationships (five times as many clubs) in the situations and consider the operations needed to describe them. They also make sense of what the unknown quantity represents in each story and how to show its relationship to the other two numbers and the quantities they represent.