How Long Are These Pencils?

This Instructional Activity is a part of the Lesson 8, Unit 9, Grade 7. In this activity, students measure lengths and determine possibilities for actual lengths. There are two layers of attending to precision involved in this task: Deciding how accurately the pencils can be measured, probably to the nearest mm or to the nearest 2 mm, but this depends on the eyesight and confidence of the student Finding the possible percent error in the measurement chosen and Finding the possible percent error in the measurement chosen.