This Instructional Activity is a part of the Lesson 10, Unit 9, Grade 7. In this activity, students use the method they came up with in the previous activity to measure the length of a path chosen by the teacher. Each group can begin working on this activity as soon as they have finished the previous activity and checked in with the teacher. It is not important that students' results are very accurate. They will measure the distance again with a trundle wheel in a later lesson. The main point of this activity is to think about measurement methods and to discuss the advantages and disadvantages of different methods.