A silly approximation of the number PI

The number PI is 3,141592....

You may note that an integer devided by 99 gives an interesting row.

If you devide 77 you get 0,77777777...
If you devide 66 you get 0,66666666...
If you devide 25 you get 0,25252525....
If you devide 13 you get 0,13131313....

So I thought, what to devide by 99, such that I get 3,14141414...

The anwer is of course 99 x 3,14141414... = 310,9999999.....

Which equals 311

So Pi can be approximated by 311 / 99 = 3,1414

If you calculate this in Excel: =PI()/311/99 you will find the error is only 0,01%