Finishing Up Surface Area - Spheres

Today was our last day of surface area. If I had time, I'd actually do one more day, since we really need a day of practice. I just can't take one more day, though, because I have to get in volume before finals. I only have two days for volume as it is (and then two days of review).

Today, we did a hands-on lesson on the surface area of a sphere. The idea was guided by Jennifer Wilson 's (@jwilson828) blog post on the Surface Area of a Sphere.

To do this activity, I knew I needed to get my hands on lots of oranges, since I have 110 kids in geometry. I called our local Food City, and -bless them- they donated 55 oranges. 1 orange per group of two. Thanks Food City!

The kids really enjoyed this activity. It was messy, but i think - sometimes - learning should be messy. The janitor didn't agree. Oh well. You can't win 'em all. The biggest problem I kept running into was that kids were skimping on filling their drawn circles. There would be lots of white space, and the kids would think they filled 6 circles. I would go around and have the groups start disassembling one circle, using those pieces to fill in the gaps.

At the end of the day, the kids had fun, and they really KNEW the formula for surface area of a sphere. Oh - AND my room smelled strongly of oranges instead of smelly high school kids. It was lovely.