Today is National Pi Day, March 14, written as 3/14. Even though the House of Representatives passed a resolution recognizing National Pi Day back in 2009, I had never heard of it. I was first aware of this celebrated day when a fellow blogger—Go Jules Go—announced that she would be submitting a pie in the Pi Day Pie Challenge being held by another blogger, Accidental Step Mom. What a fun idea! I, of course, would not enter the contest, since I am even less of a baker than I am a cook—and I am not a cook.

Still, the idea of a National Pi Day intrigued me. Even though I am more a word-person than a numbers-person, the world of numbers and its beauty and symmetry generally fascinates me. In an earlier post “The Music of Math: Just Listen” I had already explored the concept (and the sound) of Tau. Apparently, there is a controversy over the best representation of the circle constant, the traditional Pi or the proposed Tau. Since it is National Pi Day, I thought I better find out a bit more about Pi than that it is written in decimal format as 3.14.

Pi is an irrational and transcendental number that has captivated mathematicians for thousands of years. By definition, it is the mathematical constant that is the ratio of a circle’s circumference to its diameter, and is approximately equal to 3.14159. This decimal representation just keeps going and going and never repeats a pattern. These qualities make Pi an intriguing puzzle of sorts to mathematicians the world over. It has been represented by the Greek letter “π” since the mid-18^{th} century.

The San Francisco Exploratorium has been celebrating Pi Day since 1988. Typically, celebrants walk around circular areas at the facility and eat pie at the end of the march. For many years, Massachusetts Institute of Technology has postmarked its acceptance letters to new students on Pi Day. Starting in 2012, MIT has announced it will post those decisions (privately) online on Pi Day at exactly 6:28 pm, which they have called “Tau Time,” to acknowledge the controversy between Pi and Tau as the best circle constant. Princeton combines its Pi Day Activities with its annual Einstein Celebration, since March 14 is also Einstein’s birthday. There are lots of ways to celebrate Pi Day.

The Official Pi Day Website shares a wealth of information about Pi, including ideas for the classroom, a rap video about reciting Pi, news reports involving Pi, and ideas and archives about celebrations. This site also notes that it is fun to memorize and recite Pi for as many digits past the decimal point as you can. In case you want to try memorizing this number, here is a listing offered by the website providing hundreds of digits beyond the decimal point.

The Teaching Pi Website shares classroom ideas for teaching Pi and provides quotes from teachers and students about the fascination surrounding Pi. One 8^{th} grader captures this general fascination quite well: “If you think about it, pi never ends. There’s an infinite space between 3 and 4. It never ends, and that’s weird.” For me, weird is good! The website also suggests what a fun challenge it is to memorize and recite Pi, so it also gives lists of winners by grade level, noting how many digits were recited by each winner.

One student who was going to try to memorize a string of 140 digits, said it was easier to think of the challenge as memorizing 20 phone numbers than just a random string of numbers. That’s a helpful memorization tip, but no matter what the websites say, memorizing Pi does not sound like a fun challenge to me. But to give a sense of what such a recitation might sound like, here’s a video that has someone singing the number quite a few spaces beyond the decimal point:

I am still not certain how I will be celebrating National Pi Day. Maybe I’ll swing by Marie Callender’s after lunch to buy a piece of pie. I know I will listen to the video embedded below called “The Music of Pi” by Michael Blake. The fact that music is hidden in the numbers is mesmerizing to me, much more fun than someone—not me!—memorizing and reciting the numbers in order. The following video is similar to “The Music of Tau” video I presented in an earlier post. Although A Frank Angle presented this exact Pi video in his post “On a Piece of Pi” last year, it is worth sharing here as well. But don’t forget to visit his site—it offers a lot more fun information about Pi.

**HAPPY NATIONAL PI DAY!**

**HOW DO YOU PLAN TO CELEBRATE?**

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**A FINAL CAUTION:** The American Pie Council would be very disappointed if anyone were to confuse Pi Day (3/14) with Pie Day (January 23). They are really quite different, although it seems they both involve eating lots of pie.

P.S. To keep your focus on the fun of mathematics, here are two more videos. They are not about Pi, but they are fun! Enjoy!

“When Not Knowing Math Can Cost You $15,000”

“Doodling in Math Class: Infinity Elephants”

Comments on:"National Pi Day" (11)aFrankAnglesaid:What a wonderful way for me to start National Pi Day …. and with a link as well. Love the reference to Tau as I posted about it too … but you are the one who sparked that post. 🙂 http://afrankangle.wordpress.com/2011/10/04/on-a-hot-tau/ .. Happy Pi Day!

Patti Rosssaid:Thanks for stopping by. I knew you would be one who would enjoy the video and reference to Pi and Tau since we have shared this fascination before. Have a great Pi Day!

Tricia Booker Photographysaid:Great post! It is wonderful to learn more about Pi and then as a bonus have an excuse to have pie for dessert tonight!

Patti Rosssaid:Thanks for stopping by–and for the great photos you always share on your site! I love the excuse for pie this day offers, but I can find an excuse for that pretty readily. Happy Pi Day.

JM Randolphsaid:Awesome post! Thanks for the trackback!

Patti Rosssaid:You are very welcome. Your challenge started me thinking and learning, always a good combination.

Pi Day Pie Winner! | JM Randolph, accidentalstepmomsaid:[…] house in the morning because it’s one of the only reasons people come here. Go to the blog Learn More Every Day. It’s like two aspirin for your ignorance. (I’m going there a lot myself, but not for […]

Go Jules Gosaid:Thank you so much for the shout-out, I am pleased to infinity (*snort* sorry, had to) that I helped spread the pi pie word! How did you wind up celebrating??

I love the idea of Pi Day vs. Pie Day challenge.

Patti Rosssaid:You are very welcome for the shout-out–you deserve it since you introduced me to Pi Day. I did not do a whole heck of a lot to celebrate. I did some math in my head, enjoyed some math jokes from friends on FB, made plans to see a friend for lunch over the weekend to extend the celeration with pie at that time. I was even pleasantly surprised to see Pi Day discussed on Late Late Show with Craig Ferguson. I did not walk in circles or memorize numbers. Hope you had fun–your bacon chocolate Pi Pie sounded good.

yearstrickensaid:Love the Pi music. Thanks for the sharing.

Patti Rosssaid:Thanks for stopping by. The musical possibilities of math are my favorite aspects as well!