Here's an age-old trick that you can do anytime, anywhere. In an instant, you seemingly pull your thumb apart and then put it back together again. If you're an uncle or grandpa, you almost have to learn this trick to tease the kids. And if you want to truly torment a professional magician, show this trick and ask him if he knows how you did it.
The magician seemingly separates and pulls the tip of her thumb away from its base.
The magician holds the thumb between the thumb and first finger of the other hand.