Cylinders

Today grade 9s had an interesting problem to solve. We investigated the cylinders made from a sheet of paper lengthwise vs widthwise. We compared the volumes of these cylinders.

We made the connection between the page dimensions and the circumference, and then calculated the diameter and radius.

We used the radius to calculate the volume.

And then we compared the two cylinders based on their volumes.

We did a lot of great thinking today!

Finally we consolidated and learned that the more cube like the cylinder, the smaller the area will be for a given volume. So when the cylinder’s height is equal to the diameter, the area is the smallest. Or for a fixed area, the volume will be the largest.