Do you like numbers? Mathematics? Are you a lover of formulas? Maybe you are passionate about mathematical constants? If you have an interest in numbers, you’ll surely be interested in International Pi Day. Today, Pi is celebrated – the coolest constants. It is one of the first, if not *the* first constant we learn.

With this special constant you can calculate the area of a circle (A = π r²), or perimeter (circumference) using 2πr. Pi itself is derived from the ratio of a circle’s circumference to its diameter. The number produced is 3.14 or 22/7, and has been around for about 4000 years.

It has captured poets, mathematicians, artists, historians, and with people memorizing and reciting the number of digits for world records, which is currently at 70,000 digits. Pi is also evident in nature, in fact it can be also be calculated from measuring winding rivers. For me Pi is a magical constant.

So back to the first question, what are your favorite numbers/formulas/constants?

And to throw in an old pun – what is your favorite pie? (mine’s apple 😊).

Looking forward to hearing from you in the comments below.