
Continuity mistake: While the mother is driving her children to school in a minivan, both the driver's seat and the front passenger seat change from having the headrest/whiplash protector being attached to the seats (non-removable), to having the adjustable kind that have been removed.
Answer: Craps is a casino game where players bet on the outcome of a dice roll. It deals heavily with probabilities and is a favorite of math experts like Charlie. Whatever the odds, though, your chances of winning are much greater than winning the lottery.
If you bet against the roller in craps, your odds of winning are about 49%, which is as good as you get in Vegas. The point he's making (though it's pretty obscure) is that if you're going to bet, you may as well bet on something where you have a slim chance of winning, as opposed to the lottery, where your chances are basically 0.