The direction in which the vector x ^ y points can be determined with the aid of an ordinary household screw. Think of the vector x as being lined up with the slot of the screw starting at the center of the slot as shown in the figure below. Think of the vector y as starting at the center of the slot in the screw at the same point that the vector x starts and then turn the head of the screw so that the vector x turns toward the vector y in the shortest way. This will cause the screw to dig into a piece of wood in the direction x ^ y.