>47. The opposite side of a dice always add up to seven.

well, of course it depends on the purpose of your die/dice; but a standard-regulation-Las Vegas-style die has a 6 opposite the 1, a 4 opposite the 3, and a 5 opposite the 2 -- you don't often find two 6s on 1 die.

edit then of course there is the seventeen-sided die used in D&D style games.