Betting odds are the ratio between the amount staked by the bookies and the bettor, so 7/1 means the bookies stake seven times the amount the bettor has wagered. If the bettor wins; their predicted outcome materialises; they will take seven times their bet from the bookie (in this case).
The rules of the game Lucky 7 Dice  are different from card games. In card games, the goal is to predict whether the card revealed by the dealer from a suit of eight will be high (7 up), low (7 down), or equal to 7. You can also make additional bets on the suit. . or an odd/even card.