**International Day of Mathematics**or alternately, the

**Pi Day**(3/14 in the month/day format… as you know 3, 1, and 4 are the first three significant digits of

**π**which goes

**3.14159265358**….. and so on).

**Pi**(

**π**), the ratio of the circumference of a circle to its diameter, is a transcendental number whose decimal extent is infinite. It has been a fascination for mathematicians since time immemorial:

**π**.

**π**.

**π**was already known. To him then, the joy was in discovering newer ways in which one could express

**π**and developing formulae that would give more and more precise values of

**π**.

**π**up to 9 decimal places :

**3.14159265380**

**3.14159265358979265**and

**3.141592653589793238462643383279**

Then, in 1914, the *Quarterly Journal of Pure and Applied Mathematics* carried Ramanujan’s publication, titled “Modular Equations and Approximations to **π**” that contained not one, but seventeen different series that converged rapidly to **π**. Two of these were:

which gave 8 correct digits for the decimal places for each term of ‘n’ and

**π**to an astounding 4 billion decimal places using their homemade parallel computer.

**π**with an ever-increasing precision. In January this year, Timothy Mullican successfully calculated the value to a record 50 trillion decimal places after 303 days of computing!!

**π**and another transcendental number ‘

**e**‘ to any number of decimal places. In my recently published picture book biography of Ramanujan (you can read more about it here), I’ve mentioned how he had been fascinated with calculating the length of the equator – an exercise for which he would certainly have had to use

**π**.

**π**, he calculated the length of the equator to be 40,078km. Today, with supercomputers at our disposal, we know the length to be around 40,075km.

**Now, if that isn’t genius, what is?!!**