Let me related the funniest thing I've seen in a while. Everyone knows the player who isn't good at adding up his attack roll or damage and he usally end up getting it wrong or take 10 minutes. Well Saturday when another player was rolling up his damage this guy was able to call what it quickly and correctly. The DM said something like "I'm impressed" and then this player with a look of confidence in himself like none I've seen before looks up and says "Simple multiplication." The DM then asked "Simple multiplication?" and the player says " Yep". The DM asked him several times before he figured out what he was saying wrong.