This Instructional Activity is a part of the Lesson 10, Unit 9, Grade 7. In this activity, they come up with a method for measuring the walking distance of a path that is too long to measure with a measuring tape. Students will try out their method in the next activity. Students get a chance to engage in many aspects of mathematical modeling. The modeling cycle starts with formulating the question that we want to answer, clarifying which quantities are involved, and how to measure them. In many problems, this step is done for students.