The setup: You’re sitting at a cafe table facing the audience. Say: “I have a magic dime that can melt through any surface, but it needs help from a few objects. So I’m going to cover the dime with a salt shaker, and then I’m going to cover the salt shaker with a napkin. Will a volunteer come tap the shaker with my magic wand? Thank you. Now get ready—I’ll lift the shaker and you’ll see the dime fall through the table and into my hand. One … two … three!” The audience will shout that the dime remains on the table. “Argh!” you say. “Let’s try this again.” But this time, you smash your hand down on the napkin, and the salt shaker magically appears in your hand beneath the table.
• Grant is a Wharton School professor and author of Give and Take.