[math-fun] Re: mathematical cons

Have I parsed the scam correctly?

Dunno, I think (not having seen it!) that the problem is that he's using the 5 $1s that she hasn't put away yet as if they were his. So he ends up +$5. This is similar to a scam one of my high school teachers claimed was popular among his friends when he was in school. Probably works best at a drive-through. Go to Dairy Queen, buy a small cone, say $1. Make a show of looking through your wallet for small bills and then finally pay with a $20, apologizing for the large bill. After getting the $19 change and when about to leave, "find" the exact amount, tell the cashier oh look I found $1, here, can I have my $20 back? Trade $1 for $20. You walk away $18 and one ice cream cone richer. Russ