Abstract: An electric apparatus for a game includes a display unit, an operational unit, and an input unit. The display unit displays a mathematic expression including a plurality of parameters and corresponding values of the parameters. The operational unit calculates a correct answer of the mathematic expression. The input unit allows at least one player to input selected answer of the mathematic expression. The mathematic expression is displayed on the display unit before input of the selected answer. The correct answer of the mathematic expression is displayed after input of the selected answer. A method for playing a game includes displaying a mathematic expression including a plurality of parameters and values of the parameters on a display unit, inputting selected answer of the mathematic expression by at least one player, and displaying a correct answer of the mathematic expression.

Abstract: A device is provided for automatically discriminating a spot number of an upward face of a die with six faces. The device includes a signal transmitter embedded in the dice and a receiver device. The receiver device includes a set of receiver and an operation computer. The signal transmitter includes a substrate embedded in the die with respect to one of the six faces of the die. A sensor chip is mounted on the substrate. The substrate further includes four comer areas each having a conductive element mounted thereon. Each mercury switch extends upward and outward from and electrically connects to each conductive element in a manner that each mercury switch is at an angle of 15°˜75° with the substrate. Each mercury switch contains conductive mercury therein.