ROYAL HEATH TAPPIT

One of your more recognizable math based effect was Royal Heath's Tappit. From this simple effect and principle many other tricks were born. In the simple, basic effect a number was chosen on one of the tiles and the tiles were turned over. Each of the tiles was tapped as the spectator spelled his number. When the spectator had concluded spelling his number, the tile that the magician's finger or pencil was on was the selected number.