[daryn]

you're saying you have an ace in your hand, and an ace comes on the flop..

well assuming your other hole card isn't an ace, then you have seen 5 cards so far, your 2 and the 3 flop cards. that means there are 52-5= 47 unseen cards left in the deck. there are 2 remaining aces, so the chances of an ace coming on 4th st. are 2/47 or approx. 4.26%.