Pi Approximation Day celebrates the pi symbol (π) and its importance to mathematics. The symbol is a Greek letter, and it is used in mathematics to represent the ratio of the circumference of a ...

Explore the meaning and history behind Pi Approximation Day 2025, celebrated on 22 July to honor the classic fraction 22/7. Here are 17 fascinating facts about pi—from its ancient origins and ...

A facial approximation of a Stone Age woman who lived roughly 13,000 years ago. (Image credit: Susan Hayes) Facial approximations may also be skewed by biases in the underlying datasets.