RYB is quick-moving card-&-dice game for two to five players. It is available for free download from http://invisible-city.com/play/32/ryb and is scheduled for a 2002 release under the name Dragon Hatchery.
In RYB, each player controls a pool of 2 red, 2 yellow, and 2 blue six-sided dice. These dice are used to complete Goals that are played to the middle of the table. Different goals require different combinations of dice. If a player fails to complete a Goal, they can bank points on that Goal for future use, but those points are available to anyone who attemps to compete that Goal.
Each player also maintains a hand of cards. In addition to Goals, there are other cards that allow players to take, swap, and borrow dice and to re-roll failed attempts to complete a Goal.
RYB makes an excellent children's game because encourages lots of addition, subtraction, and comparison of quantities while keeping the focus of the game away from the math itself.