Why do we celebrate Pi Day?

Have you ever wondered about why we have a whole day to celebrate Pi (π)? Curious about the origin of this mysterious number? Keep reading to find out!

The concept of Pi has been around for thousands of years, starting with the ancient Babylonians who used the value of Pi (which was 3 at the time) to calculate the area of a circle. As the study of mathematics developed, so did the value of Pi. Archimedes, a famous scholar and mathematician, gave us the first real calculation of Pi by using the Pythagorean theorem. The use of the Greek symbol π began in the 1700’s and we’ve used it to represent 3.14 ever since!

The holiday celebrating this unique number was created in 1988 at the Exploratorium, a science museum in San Francisco, by a physicist working there named Larry Shaw. Pi Day became an official US holiday in 2009. It also marks Albert Einstein’s birthday. Since its creation in 1988, this holiday has most often been celebrated with pie-making, pie-eating, and fun math activities. (Via Exploratorium).

Celebrate the day with a few of the fun activities listed below! Watch your kids get excited about digging into a slice of this unique math concept.

Pi Day Activities

  • Organize a circle hunt around the house (Via We Are Teachers)

    Have your kids search high and low for any circular objects scattered around the house. Examples could be plates, clocks, coffee cups, or coasters! When the circles have been gathered, give each child a length of string and ruler to calculate the diameter and circumference of their circle. The next step is to divide the circumference by the diameter, each person should end up with a number close to 3.14 — no matter what size their circular object was!

  • Pi-lentines (Via Math Geek Mama)

    Don’t wait until next Valentine’s Day to tell your friends how much they mean! Create cards to hand out to friends or classmates celebrating your friendship on this important holiday.  Attach a note to a pencil or small calculator and write your best math pun on the card.

  • Pi Contest (Via  Imagination Soup)

    See who can memorize the most digits of pi — the winner gets a slice of pie in their favorite flavor! Use this song to help you win the contest (or impress your friends by performing it).

  • Pi Bracelets (Via Imagination Soup)

    Have you been looking for the perfect piece of jewelry that looks good AND helps you remember the digits of pi? Look no further. Use string and colored beads to color code the digits of pi on your bracelet, a perfect way to reflect your love of math and style at the same time.

  • Tell Pi Jokes

    What is a math teacher’s favorite dessert? I bet you can guess the answer… Use this list to get you started on entertaining your friends with math themed jokes. (3.14% of Sailors are PI rates!)

  • Write Pi-kus (Via Teachpi.org)

    Create your own traditional haiku- about pi (or pie). Remember the haiku is three lines, 5/7/5 syllable count. Here is an example:

    Unending digits…
    Why not keep it simple, like
    Twenty-two sevenths?

  • Make birthday cards for Albert Einstein (Via TeachPi.org)

    3/14 is more than just Pi Day — it’s Albert Einstein’s birthday! Honor his STEM legacy on this day by creating cards with Pi puns or pictures that you can hang up around the house or classroom. Find out more about his life and scientific discoveries as you craft.