Why is pi called pi? It was first called “pi” in 1706 by [the Welsh mathematician] William Jones, because pi is the first letter in the Greek word perimitros, which means “perimeter.”
What is pi facts for kids? Pi (Greek letter “π”) is the symbol used in mathematics to represent a constant — the ratio of the circumference of a circle to its diameter — which is approximately 3.14159. It is the ratio of a circle’s circumference to its diameter.
What are 5 facts about pi?
- Pi is all encompassing.
- Pi is ancient.
- We’ve used computers to calculate pi to more than 22 trillion digits.
- Humans have memorized vast stretches of pi.
- Pi has a bit part in many books and movies.
- Even rocket scientists only need a bit more than a dozen decimal places.
What’s so special about pi? No number can claim more fame than pi. But why, exactly? Defined as the ratio of the circumference of a circle to its diameter, pi, or in symbol form, π, seems a simple enough concept. But it turns out to be an “irrational number,” meaning its exact value is inherently unknowable.