Ask someone to guess how many drops of water will fit onto the surface of a nickel without the water spilling over. Most will guess between five to ten drops. Tell them that if they come within two drops of the correct answer you’ll buy them a drink. However, if they guess wrong that they must buy you a drink.

Here’s how to win every time: Place a normal nickel onto a flat surface like a bar or tabletop. Dip your straw into a glass of water, preferably yours, and retain some liquid inside by placing your thumb or index finger on top of the straw. Hold the bottom of the straw just over the surface of the nickel and allow one drop at a time to collect on the surface of the nickel (Fig. 1).

Part of the secret is doing this slowly. I recommend performing this little stunt with a standard Jefferson nickel. The raised edges on the nickel will help to contain the water on the surface of the coin. I have placed as many as twenty-three drops of water on the head-side of a Jefferson nickel and twenty-six drops of water on the tail-side of the same nickel. With a little practice you can get at least twenty drops every time on either side.

For a great follow-up gag, buy a squirting nickel. Switch nickels after the bet and ask them, “Did you ever notice the sprinkler system on Jefferson’s lawn?” When they lean in close to look squirt ‘em and be prepared to run!