# Lesson 9

Measurement Error (Part 2)

### Lesson Narrative

This lesson is optional. This is the second lesson exploring measurement error in more detail. While the previous lesson examined percent error when measurements are added together, this lesson works with percent error when measurements are multiplied. While the activities in this lesson can stand on their own, students will benefit from having done the activities in the previous lesson first.

In addition to examining accuracy of measurements carefully (MP6), students will work through examples and look for patterns (MP8) in order to hypothesize, and eventually show, how percent error behaves when measurements with error are multiplied to one another.

As with all lessons in this unit, all related standards have been addressed in prior units. This lesson provides an optional opportunity to go deeper and make connections between domains.

### Learning Goals

Teacher Facing

• Comprehend that percent error is greatest when the actual values are smaller than the measured values for an object.
• Generalize (orally) a process for calculating the maximum percent error for the area of a rectangle and volume of a rectangular prism.

### Student Facing

Let’s check how accurate our calculations are.

Building On