Only One spongeball trick Goshman
The Magician states that for his next trick, he will need three balls. Suddenly one appears in his right hand and two in his left. After allowing the audience a chance to examine these, two balls are placed into a spectators hand, the third vanishes.
The Magician now places two balls in his hand, one in his pocket. Opening his hand, there are three balls! Once more, he puts two in his left hand, one in his pocket and asks the spectator how many balls are believed to be in his hand. Regardless of the guess, he answers, "But I only have one in my hand-" then opens his hand to show the number 1!
Magic By Gosh