You show four coins on a table or desk. They are two nickels, a penny and a dime. The total value is 21 cents. You pick up one coin at a time, placing it into the palm of your left hand. You count the value of each coin as you place it into your palm, until all coins--total of 21 cents--are in your palm.
Big deal, your spectators think... With just a touch of showmanship you remove one nickel from your hand and place it into your right hand pocket. You close your left hand over the "remaining" coins and ask innocently, "how much is left?"
Your spectator answers your simple question, "16 cents". You open your fist to reveal that it is empty. The 16 cents is gone!
Your pocket and the nickel you have placed in it may be freely examined.
