Pi, or π, is defined as the ratio of the circumference of a circle to its diameter. Pi is an irrational number, meaning it cannot be written as a simple fraction. Instead, it can be expressed as an infinite, non-repeating decimal (3.14159…) or approximated as the fraction 22/7. It’s represented by the Greek letter “π”.

Museums and science centers mark the day with educational programs, music, pi memorization challenges and at least one parade, though many math fans celebrate simply by enjoying a slice of pie.

**Here are some nerdy yet fun facts for Math and Science lovers**

* The symbol for Pi has been in use for over 250 years. The symbol was introduced by William Jones, an Anglo-Welsh philologist in 1706 and made popular by the mathematician Leonhard Euler.

* Since the exact value of pi can never be calculated, we can never find the accurate area or circumference of a circle.

* March 14 or 3/14 is celebrated as pi day because of the first 3.14 are the first digits of pi.

* Although Pi day is celebrated on March 14 (3/14), the exact time for celebration is 1:59 pm so that the exact number 3.14159 can be reached.

* There is an entire language made on the number Pi. Some people love pi enough to invent a dialect in which the number of letters in the successive words are the same as the digits of pi. Mike Keith wrote an entire book, called ‘Not a Wake’ in this language.

* Pi is the secret code in Alfred Hitchcock’s Torn Curtain and in The Net starring Sandra Bullock.

* If the circumference of the earth were calculated using π rounded to only the ninth decimal place, an error of no more than one quarter of an inch in 25,000 miles would result

* The number pi was so mysterious that a Dutch-German mathematician, Ludolph van Ceulen, spent most of his life calculating the first 36 digits of pi. It is said that the first 36 numbers were engraved on his tombstone, which is now lost.

* Since there are 360 degrees in a circle and pi is intimately connected with the circle, some mathematicians were delighted to discover that the number 360 is at the 359th digit position of pi.

* Before the π symbol was used, mathematicians would describe pi in round-about ways such as “quantitas, in quam cum multipliectur diameter, proveniet circumferential,” which means “the quantity which, when the diameter is multiplied by it, yields the circumference.