Multiply Your Money Trick
Everyone would love to be able to multiply their money with nothing more than a few quick gestures but only a magician can make it happen.
The Effect
The magician holds up a small denomination coin and explains that, as much as he likes to have money in his pocket, there are times he would like to have a bit more. Right in front of the spectator’s eyes the magician takes hold of the coin with both hands and almost immediately spreads them open, to show that the one small coin has multiplied into two more valuable coins.
The Secret
Three coins - two large and one small - are held in such a way as to fool the spectator. 
Materials
One small denomination coin and two larger is all that is needed.
Preparation
Only a moment’s preparation is needed, long enough to place the three coins in the starting position, although it is important to note angles and point of view.
Performing the Trick
This trick can be done quickly as a one off bit, or as part of a larger routine. The essence of the trick is doing it right in front of the spectator’s eyes.
The starting position is assumed by holding two large coins by their edges, horizontally between inside of the right hand thumb and forefinger, and the smaller coin in front, held vertically and face forward, between the tips of the thumb and forefinger. When held at eye level it is impossible to see the two larger coins held behind the smaller, hidden as it is by the curve of the fingers themselves and the face of the smaller coin. - The magician then explains how he will multiply his money with a word. Holding the right hand up at eye level, the fingers are open and hiding nothing - at least as far as the spectator can tell.
Turning his right hand so that the smaller coin is facing the left, the magician brings both hands together, with the thumb and forefinger of each hand meeting in the middle. -
The thumb of the left hand pushes on the bottom of the small coin, causing it to rotate to the bottom of the two coin stack. Now all three coins are horizontal and hidden from view. 
The right thumb grabs the smaller coin as the left hand pinches off the top larger coin. Both coins are displayed for a visual reveal that shows the small coin transform into two larger. - It is important not to flash the hidden small coin when pulling the two larger coins apart. This flash could be visual or, more likely, audible. The small coin may “clink” as the two larger coins are pulled apart, so care must be taken to pull them apart gently.
- At this point the trick could be over or, for more impact, the smaller coin could be gotten rid of and the larger coins handed out for inspection. This could be accomplished with a bit of misdirection and simple sleight of hand.
- Hold out the left coin as you say “As you can see these are normal coins.” While a spectator is taking the left coin, allow the smaller coin to drop into the right palm for finger palming. The right hand can then pass out the right coin or, if the magician is not comfortable that it can be hidden, the left hand can take the larger coin from the right and pass it out.
- The magician can reach into the right pocket to deposit the smaller coin and pull out a handkerchief, which he can use to polish the coins as he takes them back from the spectators with an appropriately witty comment.
