[Kamog]

OK, I did some more searching around and discovered that Excel can, in fact, do this calculation.

There is a handy pre-built function called BINOMDIST(number_s, trials, probability, cumulative).
Now this is easy.

The probability of getting 182 or more 6's in 1000 rolls is:
P = 1 - BINOMDIST(181, 1000, 1/6, TRUE)
P = 0.105008

I needed to subtract from 1 because the cumulative function adds from 0 to 181. To get the portion for 182 and above, we subtract from the whole (1) the part we don't want, the stuff at 181 and below.

OK, so there's about a 10.5% chance of getting 182 or more.

The probability of getting 326 or more 6's in 1000 rolls is:

P = 1 - BINOMDIST(325, 1000, 1/6, TRUE)
P = -0.5.08482E-14

Obviously there's something wrong. The answer can't be negative. I think Excel still can't handle this kind of big / small number.

Does anybody have a better program and/or calculation method that can do this? Or am I doing something wrong?