# Pi Day – 14 March

**Pi Day** is celebrated on March 14th (3/14) by math geeks around the world. The number in the date (3/14) match the first three digits of Pi constant. The day celebrates the long history of fantastic number which start with 3.14 and goes on and on as it has no end and is infinite in length.

## What is Pi

**Pi** represent the Greek Letter **π** which is approximately 3.14 and is the ratio of any circle circumference divided by its diameter. Pi is a constant number and for all the circles in the world. Pi is the same, regardless of the circle’s size, this ratio will always equal pi. In decimal form, the value of pi is approximately3.14.

The date is 3/14/15, the first five digits in the ratio of the circumference of a circle to its diameter. At 26 minutes and 53 seconds after 9 a.m., we passed a date and time represented by the first 10 digits of π.

## History

**Pi** was discovered as early as 4,000 years ago, with the ancient **Babylonians**. A tablet was discovered from between 1900 and 1680 BCE calculated it as 3.125. A few decades later a document by an **Egyptian** mathematician listed it as 3.1605.

**Greek** mathematician Archimedes devised the first recorded algorithm for calculating the value of pi around 250 BCE.

The symbol for pi arrived in 1706 when William Jones used the Greek letter to represent the ratio of the circumference to the diameter of a circle. The symbol is not really a symbol – it is the first letter of the word periphery – **‘περιφέρεια’.**

Pi is an irrational number in that its decimal value goes on forever, never repeating. Its value has been calculated to more than 2.7 trillion digits.

Pi Day was founded in 1988 by physicist **Larry Shaw** affectionately known as the **Prince of Pi**. He celebrated the day at San Francisco’s Exploratorium science museum, where Shaw worked as a physicist. In 2009 the US Congress officially recognized March 14th as Pi Day. From those humble origins the day has grown to be celebrated around the world in many different ways. For Pi Day 2010, Google presented a Google Doodle celebrating the holiday, with the word Google laid over images of circles and pi symbols.

**Albert Einstein** was born on Pi day, March 14, 1879. . One of science’s greatest minds of all time, Albert Einstein, was born on March 14, 1879, at his family’s home in Ulm, Germany.

## How to celebrate

The pun-filled pi day is full of circular treats, like pies, pizzas, cakes, and cookies. Many might dress up like Albert Einstein, whose birthday also happens to fall on the math-filled day and the San Francisco Exploratorium still host their annual day of pi celebration.

Many people enjoy a slice of pie on the holiday, others try to memorize the digits of Pi. Teachers use this day to explain the geometric concept to students. Many businesses, like pizzerias, bakeries offer up special Pi Day recipes. Many pizza chains like Blaze Fast-Fire’d Pizza offer a custom-made 10-inch pizzas for the price of $3.14. A market in Boston special for rotisserie chicken offer a Pi Day coupon you show your coupon and get a free chicken pot pie with the purchase of an individual meal and a drink.

Pi Day is a big hit within educational institutions and among math enthusiasts. There are plenty of fun ways to observe the nerdy occasion, like reciting the number up to a certain decimal, wearing shirts with math equations and of course, enjoying a freshly baked pie. The excuse to eat pie on this day may not be entirely rational, but then again, pi is an irrational number.

It’s approximate, irrational, and circular… or you could just eat some pie on March 14 instead.

Suggested Read: National Mathematics Day