It might take you by surprise but we do have special days dedicated to the most famous mathematical constant “π (pi)”. One of those special days is the **Pi Approximation Day**. Every year, the 22 July (7^{th} month of the Gregorian calendar) is celebrated worldwide as the *pi approximation day*. It is the digits of this day which symbolizes pi approximation. 22/7 is a common approximation of pi. 22 stands for the day and 7 stands for the month of July.

## What is Pi?

**π (pi)** is an irrational number. It is the ratio of the circumference of a circle to its diameter. Digits in Pi do not repeat. So far, many attempts have been made to calculate the exact value of pi. We are getting closer with good equipment and supercomputers, but not yet arrived at the perfect result.

While we are striving to attain more accuracy, the precise value of pi is not required for everyday calculations. An approximation of 22/7 or 3.14 is enough for mathematical work in the day to day calculations.

## Importance of the Pi Approximation Day

Pi is undoubtedly an important mathematical constant. It paved the way for many modern theories in the field of mathematics and sciences. Thus, it has played a critical role in devising many formulas related circles, spheres, and other elliptical shapes. In order to reiterate the importance of pi approximation, this special day is celebrated every year. The intention behind the celebration of this day is to honor the significance of pi.

## History & Background

American physicist and curator **Lawrence N. Shaw** organized the first-ever **pi day** in 1988. This is the reason why he is also known as the founder of pi day. The first celebration of this day was held at the San Francisco Exploratorium. Later, the United States House of Representatives passed a resolution declaring 14 March (3/14) as Pi Day in 2009. Eventually, the day was officially declared as the International Mathematics Day by UNESCO in 2019. With Pi Day, the Pi approximation day has also gained significance. Though not yet officially recognized like pi day, it continues to be celebrated across the world with great enthusiasm.

## Celebration of Pi Approximation Day

Pi Approximation Day is not limited to mathematicians and students of mathematics. On this day, people eat pie!

Global events are organized with pi as the subject, or pie on the menu. Amusing, isn’t it? 🙂

## Interesting Facts about Pi

- Archimedes of Syracuse was the first mathematician to calculate pi. His calculation was that of a geometrical approach using polygons.
- It is believed that pi is an unending series of digits. It consists of all the series of number in every possible pattern. However, this fact is yet to be confirmed scientifically.
- It took humans 24 hard drives and an exclusive program to calculate pi up to
**22 trillion digits**. - Some mathematicians and physicists have advocated for replacing π with
**tau or 2 π**. According to the supporters of tau, pi is a confusing irrational number. As per them, tau is a much more relevant number considering the algebraic apostates. - Pi, up to first 100 decimal places, is equal to 3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679