Question

What is the final digit of pi, which is sometimes expressed as 22/7?

Answer 1

The decimal expansion of pi goes on forever without any known pattern. There is no "final digit". The fraction 22/7 is an approximation of pi

pi = 3.14159...

22/7 = 3.14286...

We see the values are pretty close, but not 100% the same.

Answer 2

Pi is an estimate. There is no final answer yet. People still compute this today.