## Wednesday, March 15, 2017

### Teaching Pi without pie

I love teaching Pi on 3/14. I know that my kids are a little young for some of the concepts but Pi is one of the things I love about math – the constancy.
I used to be able to bring in actual pies to celebrate with after the lesson but (SOB!) that isn’t allowed anymore….  Still, we had a lot of fun measuring and figuring out and learning about circumference and diameter.
We started out with different sized cylindrical objects. Students paired off with face partners and were assigned a round object. They took the object and traced the circle on a piece of paper. They then used a string to measure the circumference of the circle. After logging the circumference in centimeters, the students cut out the circle and folded it in half. They used the fold to measure the diameter and cut the measured string into 3 diameters. There was a little bit of string left over.
The class then called out, by team, their circumference measurements, which were entered on the board. The circumference was divided by the diameter, and the results were recorded.
Once the kids realized the goal was to be the closest to 3.14, they gasped as each measurement was announced. Tension mounted and then one team actually measured 3.142 which was the closest to Pi that we came! The kids applauded and we all celebrated (but without pie, SOB!)
We brainstormed why the results were different from team to team, and eventually decided that the more exact the measurement and cutting, the closer to Pi you get. We ended the lesson by watching different people on the internet recite Pi.                                                     I know the next time Pi comes up, my kids will remember this lesson. I just wish we could have remembered it with apple (or blueberry or cherry or rhubarb…)