You approach your audience with a closed fist and ask someone to guess what's inside. Finally, you tell them, "8 balls." With that you open your hand to reveal three miniature rubber 8-balls. You place one in your pocket and close your hand around the other two. In a wink, your hand is opened to reveal - 8-balls, but three instead of two. Again, you place a ball in your pocket and again it appears back in your hand. Finally, you try one more time. But this time when you open your hand there's only one ball, but it's a full - size rubber replica of an 8-ball.