National Pi Day: Math Pie-jinks

Pi Day is a modern holiday commemorating the ancient mathematical constant π (pi), or approximately 3.14. Pi Day is celebrated each year on March 14.

Get it? March 14 = 3.14 = π. Heh.

As you will [no doubt!] recall, π is the ratio of the circumference of a circle [the distance around] to its diameter [the distance across the middle]. [And yes, this *will* be on the test.] If you have trouble remembering, this catchy Pi rap may help.

This π ratio works on little circles [mini tarts, biscuits, round cookies] as well as big circles [full-fledged pies, quiches, casseroles].  Find the area of your circle [how big it is] with the handy formula A=π r2 .

An irrational number, Pi never ends [the number goes on and on after the decimal] and never repeats.

Nerd practical joke:
Ask a friend to read this formula aloud:” π r2.” [pronounced “pie r squared”]
You respond: “Pies are not square; they’re round!”

Coined by physicist Larry Shaw [dubbed the “Prince of Pi“] back in the 1980s, Pi Day has been an occasion to generate interest in math and sciences, and to eat lots of pie. In 2009, the United States House of Representatives made it official, and designated March 14 National Pi Day.

Some people go a little crazy with the Pi – pie thing:

  • Aerospace corporation Raytheon gives out pies to all the schools within a 3.14 mile radius of their offices on Pi day.
  • Food blog Serious Eats has a Pi Day Pie Contest that gets hundreds of entries.
  • Progressive rock musician Kate Bush performed a song titled π on her 2005 album Aerial, in which she sings pi to its 137th decimal place.
  • Several cities host Pi Day runs that gives you good reason to carb-load on pies before you burn off all those calories with a half marathon.
  • At the Exploratorium in San Francisco [where Pi Day began], there’s a Pi Procession that goes 3.14 times around the Pi Shrine. Participants then eat pie “while it lasts.” Organizers say that, while the number Pi goes on forever, “some pi[e] is not infinite.”

As for us, we’ll have a quiet, pie-focused Pi Day celebration. Our greatest challenge will be choosing which pie to make! We’ll have Chicken Pot Pie for starters. And for dessert, we’ve narrowed it down to Pecan Pie, Maple Pumpkin Pie, or Apple Pie. With homemade Vanilla Ice Cream and/or Honey Vanilla Whipped Cream on top.

Still need even more pi[e]? We’ve got a whole batch of pie recipes at this link.

Photo credit: Pi Pie (π-Kuchen), hergestellt an der Technischen Universität Delft.

For extra credit: Do this exercise on calculating Pi by throwing frozen hot dogs.