Drop the washers down the slot and watch it bounce from peg to peg. Where it will end up no one knows.
Ways to play.. give them 3 washers and let them get 3 in a row, 3 in the same color, 2 in the same color, etc.) Or make it harder and give them 1 washer and have them get it in the correct color. You can even let them choose what color if you want to.