Michael Moeller, age 11, of San Diego, Calif., for his question:

WHO INVENTED DICE?

Dice are small cubes used in games. They can be made of ivory, bone, wood or hard plastic. The six sides are numbered by dots from one to six, so placed that the sum of the dots on a side and the opposite side always equals seven. The cubes are used to play games or to gamble.

We don't know who invented dice. But we know they were found in ancient Egyptian tombs and in the ruins of Babylon. The playing of dice was also popular in Greece and even more so in Rome. Dice were also used for playing games throughout the Middle Ages.

The most popular dice game in North America is called craps. The game is often played in legal gambling casinos. Two cubes together are called dice. If you had just one cube, it could be called a die.