Let Them Eat Pi

In case you missed it, today is Pi Day.

What?  You’ve never heard of it?  Well, somehow, in the last few years, the nerds got themselves their very own day and convinced the non-nerd populace to go along with it.  So schools and bakeries and Facebook posts around the country spend March 14th geeking out.

This year, our small group of homeschoolers decided to jump on the bandwagon and join the fun.  If you want to pull off a similar geek-bash, here’s what we did:

We read the first half of a wonderful picture book called Sir Cumference And The Dragon Of Pi, about a knight who was accidentally turned into a dragon, and whose son Radius must find the right amount of potion to give his father in order to return him to human form and avoid being killed as a dragon.  In order to do this, Radius must discover the ratio pi, which he learns is the circumference of a circle divided by the diameter.

At the point where we left off, Radius has learned that if he lays strips of pie crust across the pie to form a wagon wheel lattice atop the pie, it will take just over three of those diameter-length strips to go around the edge of the pie.  But how much than three strip would he need?  When he discovers that number, he’ll know how much potion to give his father…

I put the book down at this point and said that I wasn’t going to read the rest of the book until we figured out the answer ourselves.  I gave four teams of two students several circles, a ruler, some string, a pencil, and a calculator.  They had to find the diameter and circumference of each circle and then divide the circumference by the diameter.  When they finished, they came back together and compared their answers.  To everyone’s delight, they were all very close to 3.14.

We talked for a minute about why our answers weren’t all the same (as the book had predicted), and then we talked for another minute about the number 3.14… and the Greek letter pi.  After a minute of that, we served up delicious pie that two of the other mothers had made.  While we ate, we finished the book, where I learned that pi without the e was given that name in honor of Radius discovering the necessary amount of potion by playing with pie crust.

What?  You don’t believe me?  Then you just don’t understand the nerd magic of pi day.