This Instructional Activity is a part of the Lesson 12, Unit 3, Grade 6. In this activity, students explore percentages that describe parts of a whole. They find both B and C, where A% of B is C, in the context of available and consumed water on a hike. Students who use a double number line may notice that the value of B is the same in both questions, so the same double number line can be used to solve both parts of the problem. To solve the second question, however, the diagram needs to be partitioned with more tick marks.