 Disguised as a gypsy, Hacker lures Digit to a fantastic cyber amusement park and holds him captive. When the kids arrive, they analyze the games of chance, figuring out which games are fair and which ones are not, and use what they learn to find Hacker and beat him at his own game before it s too late! The Big Idea: A game of chance is fair when nobody can tell who will win, but everyone has the same chance of being a winner. (Math topic: probability and chance.)