The Greek letter ‘pi’ (π) is a unique number and is defined as the ratio of a circle’s circumference to its diameter. This number is independent of the size of a circle and for all practical purposes, its approximate value is taken as 22/7 or 3.1416. In fact, the fraction 22/7 is slightly greater in value than ‘pi’. For many centuries mathematicians have been fascinated by its unique characteristic. The strangest thing about this number is that nobody has been able to calculate its exact value. Computer scientists have now computed ‘pi’ to over one million decimal places. At one time the scientists tried to prove that ‘pi’ was a fraction. When any fraction is written as a decimal, the same digits always appear over and over again in a specific pattern. If ‘pi’ were a fraction, there would be a repeating pattern to its digits. But strangely enough, a repeating pattern in ‘pi’ could not be found. Finally in 1761, a Swiss mathematician named Johann Heinrich Lambert settled the matter once and for all. He proved that ‘pi’ is not a fraction. Now the question arises — what is the significance of ‘pi’ in our daily life? Suppose you have an automobile tyre whose diameter is one metre. If you want to find its circumference, you can find it out by measuring with a tape. Another way of finding the circumference is to multiply the diameter by this strange number ‘pi’. This number is used to calculate the circumference of all the circular objects. Mathematicians today are still engaged in research to find out if the digits of ‘pi’ are arranged in any specific manner.