If you perform this "observation test" at the beginning of your Close Up or Parlor program, your audience will think you need to see an eye doctor right at the start.
What happens? You announce that you want to test the audience's attention with a real two-euro piece and a copper one-cent piece.
Cent and two-Euro are on your left hand. Clearly visible, you take the cent away, put it in your jacket pocket and close the hand that still holds the Two Euros. If you ask your spectators what is in the closed hand, you will get the answer: Two euros. At the same time you open your hand and show that the cent, which you visibly put into your pocket before, is also still in your hand.

Was the cent too small to watch closely? You give the spectators another chance. This time with the larger two-euro piece, which you clearly visibly take out of your hand and put into your pocket. What is now in your closed hand? Right, the cent, of course.

But if you open your hand, your spectators will almost be struck: Because in your hand is no longer the cent that everyone knows, but a giant dime 40 mm in diameter that makes a huge noise when you throw it on the table for examination. But wait, a two-Euro Coin also played a role in the observation test. And while you are thinking about it, a huge two-euro piece (70 mm in diameter !!!!) appears in your empty hand as the crowning glory, almost slaying your spectators.

To the two exactly reproduced giant coins you receive the routine which helps you that also you can show this unbeatable scoop after approx. 10 minutes trying out.