This game may be played as "Blackjack" in Las Vegas for big bucks, but you can play without any money and teach your kids a little math in the family-friendly version. As the adult, you should play the dealer role. Deal your kids one card, face up, around the circle, then one to yourself facedown. Then deal another one faceup to each player and one more faceup for yourself. Forget the Vegas rules with the splitting pairs and doubling down -- they can learn all that stuff later. Just go around the circle one at a time and ask if they want to hit or stay, with the object getting as close to 21 as possible without going over. At the end of the line, turn over your cards and see who won. Each round in the family-friendly version counts as its own little game, or you can assign a point value in place of winning chips.