Irrational number

[SheeppOSU]

if you check the digits of the number for a period.....?

You could I guess check for repetition in the digits, then if so declare it rational. Then if there is no repetition in a long float then I supposed you could declare it most likely irrational, but I could have a digit of 10000 decimal places and it's still rational because it ends. An irrational number is a number in which it's digits go on forever, so it's hard to measure that.I don't know much about proving irrational numbers but if there happens to be some algorithm or method out there to do so you could possibly implement it. Though I'd assume different irrational constants are proved irrational through various methods.