He places a small 25P or Nickel etc. coin under the first rubber band. He then shows money has doubled, showing a coin now on both sides of the paddle. He repeats this with a second, then third coin, showing he has respectively four and six coins! He then removes all six coins, showing that they are all separate and for real! That's only small change, how about something a little larger? Paddle is again shown blank on both sides.
Bang! There appears a real Currency Note, a Fiver! It is removed, and paddle again shown blank. How about something a little larger?
Bang! There appears a Hundred buck Bill! or a tenner, if you're not used to carrying around large Notes The spectator is now more puzzled than even before. Well, he asks, how is it done? After again showing paddle blank, he answers the spectators question. With mirrors, the magician explains, and there appears a mirror! Oh my gosh, what a trick!
And for the final kicker, all can be examined to his heart's content. A pocket trick with a big impact.