## Pi Day 2015

**Pi Day 2015 - Celebrating one of math's greatest numbers**

At 9:27 am this Saturday, scientists and mathematicians around the world celebrated a one-in-100-year event in a special and somewhat bizarre manner.

International Pi Day, which honours one of the world's most recognisable mathematical symbols, is traditionally celebrated on March 14 at 1.59 pm – a date and time that gives the first six digits of the number pi (3.14159) in the US date format.

This year, Pi Day falls on 3/14/15 – a sequence that won't occur for another century. Although some pi enthusiasts will stick to the traditional time, many will kick off celebrations at 9.27am, permitting them to indulge in a further two digits (3.1415927) of their beloved irrational number.

Pi, represented by the Greek letter, is the ratio of the circumference of a circle to its diameter. It is an irrational number, so its digits never end or repeat. Pi helped ancient Egypt build the pyramids and has aided in the discovery of the Higgs boson or "God particle".

Competition between the world's top mathematicians to calculate pi to ever more decimal places has set the record at eight quadrillion digits.

Pi Day involves pi-related activities such as parading in a circle and reciting as many digits of pi as can be remembered, creating pi puns (What do you get if you divide the circumference of a jack-o'-lantern by its diameter? Pumpkin pi) and, of course, eating pie. It was founded in 1988 by physicist Larry Shaw at the San Francisco Exploratorium.

In March 2009, the US Congress passed a resolution recognising March 14 as National Pi Day.