Four in One - Half Dollar - Eisenhower Dollar
The magician shows four Eisenhower dollar coins in his hand, then takes one of the coins and brings his pocket, when you reopen your hand has 4 coins again.
Returns to remove a coin from his hand and takes her to his pocket but when you open your hand has 4 coins. Repeat this 2 times and always has 4 coins.
Finally it shows the 4 coins in his hand and takes a pocket to carry it when you open your hand and the other coins have disappeared.