Countdown! takes the gameplay of Shut the Box (the addictive dice game) and turns it into a two player game. Each player has keys from 1-10 and they must try to flip them all over by rolling the two dice and forming a mathematical equation using the two dice. Whatever the answer to the equation is determines which key can be flipped over. You can use addition, subtraction, multiplication, and division. The twist is that if you roll eleven, your opponent has to reset all of their keys, and if you roll twelve you have to reset all of yours. Great game for teaching kids basic math skills. - BoardGameGeek