Cylinders and Scale

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What It Is (continued)

Have the students make a number of scaled-up cylinders by doubling, tripling, etc., the height and circumference of the unit rectangle. Butcher paper works well for the double-, triple-, and quadruple-sized cylinders. Use stiffer tagboard or old file folders for the next few sizes. To make a doubled cylinder, one side of the rectangle is equal to h X 2 and the other side is c X 2 (see illustration). As students measure and cut out rectangles for larger cylinders, it is a good idea to have them trace their outlines on a sheet of chart paper before they tape them up into cylinders. This provides a convenient resource for comparison, measurements, and display of results. Some students have found it useful to have these outlines color-coded by size.

Measuring for Linear Dimensions

Each student group should start with a blank version of the chart (available here). In the first session, they measure the linear dimensions and the area of the sides. There are two ways to make these linear and area measurements. The first method has the students measuring the lengths in centimeters and the areas in number of square centimeters covered.