Bike Design

Unit Plan

By Page Bird

As part of our assignment we were to incorporate some real-world mathemtics into our unit or a project. As a middle school teacher (sixth grade) I thought my students would be particularly interested in bicycle design and the mathematics that are invovled. So I have created a unit with this purpose in mind.

Day 1 and Day 2: Begins with a look at a web page that takes a comprehensive look at bicycles. I have created a worksheet that students will use as they go through the web site.

Day 3 and Day 4: I found a great lesson plan on PBS regarding the geometry of bicycle design. I wanted to include this lesson as part of my unit. The lesson does not require any special technology. But fortunately it requires measurement, uses ratios, and focuses on geometry.

Day 5 and 6: For this day, students will focus on the center of gravity. In the web pages and articles that they have looked at so far, there are several mentions of the center of gravtiy for bicycles. So I thought that students could look at triangles to gain a better understanding of center of gravity. On this day, students will start out using GSP to look at the center of gravity for a triangle. Click here to see an example. The centroid of a triangle is the center of gravity for a triangle. Students will then continue to investigate the centroid of a triangle by using carboard triangles and a pencil point or a tennis ball in a cup to estimate the center of gravity. They will then construct the centroid to compare with their estimation.

Day 7 and 8: Students will use a spreadsheet to look at the number of rotations needed to travel different distances. Students will use the formula circumference equals two times the radius times pi. Depending on students' familarity with spreadsheets, this lesson could take a couple of days.

Day 9 and Day 10: For this part of the unit, students will use traditional constructions to design a bicyle. After, using traditional constructions, students will then use GSP to design the same bicycle.