Paper Plate Protractor Craft for Sir Cumference and the Great Knight of Angleland

We've had a lot of fun with geometry lately, but I've noticed the children having trouble with all the big words - circumference, diameter, radius, acute, obtuse, and so on. It's not that they're not interested in geometry, because really geometry is pretty neat. And, as we learned from Eratosthenes, it can come in handy. It's just a lot to learn.

To make things easier I turned, as usual, to Cyberchase, PBS's animated, math-themed series for children, and also to the Sir Cumference series by Cindy Neuschwander, that integrates math terms into medieval type stories about knights, and ladies. My hope is a double shot of Sir Cumference, and Cyberchase, paired with a hands on activity, or two, will not only provide a good introduction to geometry, but also help the children remember all the big words, that go along with it.

The first book of the series to arrive in from the library was Sir Cumference and the Great Knight of Angleland. In it Squire Radius, heads off on a knightly quest to save a neighboring king. His parents, Sir Cumference and Lady Di of Ameter, present him with an old family heirloom, a circular medallion, to give him courage. He quickly discovers the numbers along the top of the circle, can help him to measure the size of turns, and corners, as he navigate through a dangerous labyrinth, where the king is trapped.

Along the way the reader is introduced to degrees, right, straight, acute, and obtuse angles, as well as parallel lines, and Radius is promoted from squire to knight.

Similarly, the Cyberchase gang, must learn to measure angles by degree, in order to follow a map from Motherboard, to a very special, pirate treasure, in episode 205 - "All The Right Angles". There is a game to go along with it, on the PBS Kids' website, but to view the episode, you'll have to look to your local library, or YouTube (where the link above, on the episode title, will take you).

Neuschwander invites her readers to join in the fun too, with the medallion (or protractor) at the back of the book. Of course, since our copy came from the library, the medallion had been removed. So, for our hands on activity, I had the children decorate their own medallions.

I got them started, by cutting half of the center portion, out of a few paper plates. For the younger children I drew lines in for the degrees. The ridges, along the edge of the plates, line up perfectly with five degree measurements, so they were very easy to fill in, and I let the older children do that part themselves, with an actual protractor to check their work.

I set the table the plate medallions, along with a pencil, and an orange, and yellow crayon, for each child, so they could decorate the medallions, while I read the story to them.


Then, when we were done reading, they used their protractors to measure the angles around the house, like the corners of our supersized tangram pieces.


It's great to be a homeschooler.