This Instructional Activity is a part of the Lesson 3, Unit 5, Grade 7. In this activity, students use the relative position of numbers on the number line to compare them. Instead of working with specific given numbers, they start with two different, arbitrary lengths. They use these lengths to label various points on a number line. Students see that even though each group may have worked with different lengths, they should still get the same answers to the final set of questions, because everyone started with a > b.