# Get irrational: 3.14 things to do on Pi Day

March 14 is Pi Day, which celebrates the mathematical constant measuring the ratio of a circle's circumference to its diameter (beginning with 3.14). Pi Day is celebrated internationally, and in 2009 it was decreed an official holiday by the US House of Representatives. Here are 3.14 ways to celebrate.

## 1. Take a Pi Day challenge

How many digits of pi can you name? Lots of people remember 3.14. Some can push it to 3.1415926535. But no one can name them all. Pi has an infinite number of digits. The numbers go on forever and seem to never repeat themselves.

People all over the world memorize as much of the mathematical constant as they can and compete for the recognition.

How much can these avid pi-lovers recite? The current record holder, Chau Lu, recited up to the 67,890th place of pi in November 2005, according to the Pi World Rankings List. Lu had previously practiced in front of classmates in school, but his record-breaking recitation was his first public attempt.

Lu told the Pi World Rankings List staff that it took him one year to memorize the digits. The recitation alone took 24 hours and 4 seconds, with no lunch nor bathroom break in between.

Pi recitation contests are held in public schools, colleges, and museums all over the United States, as well as in other parts of the world.

One of the best known contests is held in Princeton, N.J. The town celebrates Pi Day and Albert Einstein's birthday (also 3/14) with food, parties, and pi recitations, according to the town website. The winner gets $314.59, courtesy of the town's mascot, the black squirrel.

Other pi recitation contests are at the Maryland Science Center and Massachusetts Institute of Technology, where winners have received $20 to $50 prizes in gift certificates.

If reciting hundreds and thousands of digits in order seems daunting, there are other educational activities people take part in on Pi Day. Flex your brain with a paper plane designing contest or a puzzle. One venue in San Francisco is holding a puzzle party as part of the local “Ask a Scientist” series. Teams of up to six people will compete with pencils, paper, and basic calculators.

The series, which started in 2003, brings an expert to cafes and other casual venues around the Bay Area to lead casual discussions about science.