Today, March 14, is **Pi Day**. 3/14 is celebrated every year and many of us are REALLY excited about next year because it will be 3/14/15! In honor of this special day, today's blog is a series of fun graphics, ideas, & pins that you can use in your own Pi Day festivities.

Want to have your own Pi Day celebration but are not really sure what to do? Here are some of my favorite activities:

**Eat Pi**

Most students erroneously think pi "is" 3.14. In fact, correcting this accuracy-related misperception is one of my primary goals each Pi Day. What is interesting is that even those students who know the common decimal approximation for pi often do not know the common fraction approximation, 22/7. Obtaining that piece of knowledge is the goal of my "eat pi" activities. Basically, the premise is simple: everyone has to eat pi, literally. Everyone brings round food: pizza, cookies, pi (of course!), etc. that is cut into 7 slices. It is best if the round food is a rather small diameter so the slices are not very big since the objective for this activity is to EAT PI, meaning everyone has to eat 22/7 or 22 slices of things cut into sevenths. I've done this activity with elementary age students through college adults and every time it's a huge hit! They love it! Even better, I have former students who are still in contact with me now, years and years later, and tell me they have never forgotten 22/7 as the common fraction approximation for pi. Now THAT'S a sweet activity!

**Measure Pi**

It's amazing how powerful a simple hands-on activity can be. For this one, you just need a large collection of round, circular objects of different sizes. This can include coins, lids, plates, CDs, bicycle tires, etc. You'll also need string, a ruler, and a meter / yard stick. Participants will measure various items using the string to measure the *circumference* (distance around the circle) and the *diameter* (distance across the circle that goes through the center). I love utilizing technology like Excel in examining the data. Here's a screenshot of some results when I've done this with a group of teachers:

**Approximate Pi**

There are so many interesting and counterintuitive methods to approximate pi! I will mention two of my favorites here: a hands-on version that uses thumbtacks and a red solo cup and a technology-based version called Buffon's Needle that incorporates a bit of history of math in the process. Both versions use a surprising act (tossing thumbtacks from a cup and tossing needles on a lined paper) to "discover" pi in certain ratios. For the hands-on version, you simply have participants drop a cup-full of thumbtacks and keep track of how many land point-up and how many land on their side. Buffon's Needle, named for Georges Louis Leclerc (later Count de Buffon), involved dropping needles on lined paper and keeping track of when the needles crossed a line and when they didn't. Obviously, this may NOT be a great in-school activity! Fortunately, there are many online simulations like this one and this one. Also, you can use software like The Geometer's Sketchpad to create your own simulation like the one shown here:

**Find Yourself in Pi**

Teachers I work with often mention that finding fun pi activities to use with younger students is a challenge. One of my favorites is "find yourself in pi" -- I love it because it's so simple and the students get such joy out of doing it. Here's what you do: choose a number sequence that means something to you. For example, I might pick 0806 because my birthday is August 6th. Then, using one of the wonderful online tools like this one, search for yourself (meaning your numeric string) in pi. It will show you results like this:

**Create Pi**

Pi Day Activities can also include art and creativity. For example, students could create a Pi-themed comic book or animate a Pi-related story using Alice or a similar programming tool.

Here are a few pins from Pinterest that celebrate this special occasion. Remember that it is also a fun edtech project for your students or children to have them create their own Pi-related graphics or pins. Be creative!

I especially love the pin about Pi-Ku, creating a Haiku-like poem that follows the 3 syllables, 1 syllable, 4 syllables format. Try it!

Finally, I leave you with a graphic from Second Life illustrating that, even in virtual worlds. Pi Day is celebrated!

I hope you've enjoyed the Pi Party! As always, I'd love to hear from you.

**Note:** Hope you enjoyed that I decided to publish this at 2 pi o'clock! :-)

**References:**

Rimwe's Math Board on Pinterest (with several Pi pins)

The Joy of Pi

Pi Pages (where you can listen to Pi, in French no less)

Exploratorium's PiDay 2014 page

Pi in Second Life

Wearing Pi activity giving real life context to hat sizes

The Pi Search page

**The Solver Blog**

**Author: Dr. Diana S. Perdue**