Eli5: I always thought pi is 22/7, but recently i found out that 22/7 is a number that is pretty close to pi, not pi itself. Then how do mathematicians found more “pi” ?

Question

Eli5: I always thought pi is 22/7, but recently i found out that 22/7 is a number that is pretty close to pi, not pi itself. Then how do mathematicians found more “pi” ?

In: 167

Answer 1

There are many ways to find pi, usually they involve repetitive calculations that you can do over and over again to find more digits.

One easy (and VERY inefficient) series is

4 – 4/3 + 4/5 – 4/7 + 4/9 – 4/11…

which will very slowly converge to pi.