This is one of those unusual, if not bizarre, effects. You borrow a coin and proceed to bite a chunk from it, Displaying the 'bitten coin' while you happily chomp away on the missing segment. Then holding the coin in front of your mouth, you 'spit' the chewed segment back onto the coin. The coin seems to heal instantly before their eyes. Smart, eye popping, visual magic. So unusual they'll just have to talk about it ... and therefore you!! (10p coin)