Lesson 8: Measurement Error (Part 1)

Let’s check how accurate our measurements are.

8.1: How Long Are These Pencils?

Two pencils, one significantly shorter than the other, are indicated by a ruler with millimeter and centimeter markings. The top pencil’s eraser lines up with 0 and the tip ends between 5 point 3 and 5 point 5 centimeters. The bottom pencil’s eraser lines up with the 0 and the tip ends between 17 point 6 and 17 point 8 centimeters.
  1. Estimate the length of each pencil.
  2. How accurate are your estimates?

  3. For each estimate, what is the largest possible percent error?

8.2: How Long Are These Floor Boards?

A wood floor is made by laying multiple boards end to end. Each board is measured with a maximum percent error of 5%. What is the maximum percent error for the total length of the floor?