Performance:
The magician ask the spectators for 3 bills, takes the first and places it in his left hand. Now he takes the second bill und place it in his left hand, too. And the last bill goes into his pocket. The magician asks now: "How many bills I have in my hand?"  2? No. There are still 3 bills in his hand.
Same thing again: 2 Bills in the magicians hand, one in his pocket.And again: Still 3 bills in the hand.
One last time: 2 bills in his hand, 1 in his pocket, but now the magician made all the money disappear.

The secret:
To do this trick, you need one more bill. Before performing the trick, fold the bill a few times ( 4 times should be enough) so you can place the bill in finger palm (right hand). Now you can ask your spectators for 3 bills, or you use your own. Doesn´t matter, but it´s more impressive, if you do the trick with borrowed money.
Fold the bills to the same sice like the bill in your right hand.
Now take the first bill with you right hand ( it looks more natural, when your right hand with the bill has sth. to do)
and place it in you left hand. Take the 2. bill and this time also place your palmed bill in your left hand. Act like you put the last bill in your pocket and bring it out again (finger palmed ).
Now Ask the spectators, how many bills you have in your left hand, and show them the 3 bills.
Do the same thing again, but this time, left the 3. bill in your pocket, so you have nothing in you hand.
Again: Ask, how many bills you have in you left hand and show the spectators the 3 bills.
Last time: Now take 2 bills at once and act like you place them in your right hand, and when you place the last bill in your poket, simply let all 3 bills in you pocket.
Ask the spectator one last time how many bills you have in your left hand. Perhaps they will say you have 3 bills. If they do you can laugh and say : "Nice guess, but this trick is over"
And reveal you empty hands.

Done