I asked somewhere else, but got no response. Maybe someone here can help me understand this image. When solving for a particular value of i where i == digit, am I correct in converting that image to this ? answer = 1/16^digit * (4/8*digit+1 - 2/8*digit+4 - 1/8*digit+5 - 1/8*digit+6) is a multiplication implied with number(number) in that image ? thanks

Minor correction (should be): (1/(16^i)) * (4/(8*i+1) - 2/(8*i+4) - 1/(8*i+5) - 1/(8*i+6)) Otherwise you would be doing (4/8) * (i+1)... which would be wrong. And yes, excluding the first those appear to be multiplications rather than exponents.

Thanks, but even with the extra parenthesis and correct order of precedence, i'm still getting a wrong result. ie: for i = 5 answer = 9.5367431640625e-07 * (0.097561 - 0.045455 - 0.022222 - 0.021739) insanely small number. As this formula is supposed to calculate a digit (i) of pi, the 5th digit should be 9. Unless i'm understanding this wrong ? url to formula explanation

http://www.math.hmc.edu/funfacts/ffiles/20010.5.shtml not familiar with this equation, but it looks like it should work just like you want.... except it's in hexadecimal (hence the reason you see 1/16th at the front, and not 1/10th).

Ahh yeah, the Wiki you were reading kind of separates the Hexidecimal part... I thought you were looking at this which says