It's the only holiday to honor a number: Pi Day, on 3-14, the beginning digits of the infinite, nonrepeating decimal expansion of $\pi$ = 3.1415926... As the ratio of a circle's circumference to its diameter, $\pi$ is irrational and transcendental--qualities sure to bring a twinkle to any mathematician's eyes. How are people celebrating Pi Day?

- In Rhode Island, the AMS will be holding our annual
*Who Wants to Be a Mathematician*game with local high school students.

- How about some music? Here's Noam Elkies' composition, Steganographic Étude #1, based on the first 244 digits of $\pi$, with an explanation.
- Who came up with Pi Day? Learn about the day's history.
- The Exploratorium in San Francisco hosts events every year
- National Council of Teachers of Math (NCTM) "Pi Day on Pinterest"
- Math Goodies offers lesson plans
- College and university math departments such as Princeton University, Missouri University of Science & Technology, Harvard University, University of Adelaide (Vine videos), and MIT have fun on Pi Day
- Uppsala University (Sweden) student memorizes and writes 3141 digits of $\pi$.
- Raytheon's Math Moves U celebrates Pi Day. Make a pie!
- See Happy Pi Day video on YouTube. Dr Eugenia Cheng, from the University of Sheffield, explains what Pi is, what it's useful for, and demonstrates a trick to remembering it.
- Read more about Pi Day on AMS Blogs:
*The Pi Day Link Roundup of the Century*, by Evelyn Lamb,*Pi Day and Other Math Holidays*, by Maya Sharma, and*The Ubiquity of Pi Day: It’s Not Just for Math Geeks*, by Edray Goins. - Search Twitter for hashtag #PiDay to see lots more Pi Day celebrations around the world

Email the AMS Public Awareness Office

From *The Self-Referential Cookbook*: the first 13 digits of Pi (last displayed digit rounded).