Pi Approximation Day is celebrated on July 22. It is dedicated to the famous number Pi, which is denoted by the Greek letter pi, and approaches 3.14. Of course, mathematicians take this date seriously, but many prefer to celebrate in a playful way and bake pies in honor of the event. By the way, the number pi is used for many mathematical calculations.

## The History

Pi has a history of more than 4,000 years. The ancient Babylonians rounded it up to 3.125 and used it to calculate the size of a circle. Archimedes was the first to make a discovery in 250 BC; he calculated that the number Pi is between 3 1/7 and 3 10/71. Another name for this number is the Archimedes constant. A little later, the calculations of Archimedes were confirmed by the mathematician Zu Chongzhi. The fact is, the works of Archimedes were lost and the Chinese scientist himself carried out the calculations, but used a new technique. India also made its own calculations between 1400 and 1500 AD, and in the 17th century, Austrian astronomer Christoph Greenberger calculated 38 digits of pi. In the middle of the last century, the pi was first calculated by a machine to 2037 digits.

## Interesting Facts

- It wasn’t until the 18th century that the Greek letter pi was used to denote the number pi. This version was proposed by the Welsh mathematician William Johnson.
- In 1973, one million digits of pi were calculated.
- Emma Haruka Iwao, an employee of Google, calculated the largest number of digits; she managed to determine 31 trillion digits. This result is included in the Guinness Book of Records.
- WIT University student Rajveer Mina memorized 70,000 digits of Pi, and it took 10 hours to read them out.
- The ancient Greek pyramids were built using the number pi.

## How to take part

Bake a pi cake, or learn as many digits of pi as you can, it improves your memory and makes you a more interesting conversationalist and intellectual. Have a competition with your friends to see who knows more digits of pi.

## When is Pi Approximation Day celebrated in 2023?

Pi Approximation Day is observed on July 22 each year.

### Observations

Weekday |
Month |
Day |
Year |

Saturday | July | 22 | 2023 |

Monday | July | 22 | 2024 |

Tuesday | July | 22 | 2025 |

Wednesday | July | 22 | 2026 |