# Lesson 12

Using a Trundle Wheel to Measure Distances

### Lesson Narrative

This lesson is optional. In the third lesson of this sequence, students use their trundle wheels to re-measure the distance from the first lesson. After students have had experiences using their trundle wheels, they can connect their observations of how the wheel works with the distance computations and discuss the sources of errors in a more meaningful way. Students engage in important parts of mathematical modeling (MP4), they use appropriate tools (MP5), and attend to precision (MP6).

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

• Calculate the distance of a path using the circumference and number of rotations of a trundle wheel.
• Compare measurement calculations and express differences between measurements as a percentage.
• Critique (orally) methods for measuring a long distance.

### Student Facing

Let’s use our trundle wheels.

### Required Preparation

Prepare to distribute the trundle wheels students built in the previous lesson. Make sure students can still get to the path (between 50 and 100 meters) that they measured the other day.