All you need is a 2-liter bottle of whatever. In this case, it was a Mello Yello.
Fill it with water.
Now, grab a quarter (or a coin, it doesn’t matter), place it below the bottle and ask your know-it-all daughter (or friend) to look at it through the opening.
Now, fool the know-it-all with a plastic bag. Cover the bottle with it and pretend you’re doing something mystical. You can chant here, but it’s not necessary.
Now, remove the bag. Ask the know-it-all to see if the coin is still there.
Well, you’re going to have to watch the video for the final step.
Wasn’t that great?