You're holding in your hand two coins, half a dollar and a penny. You openly take the half dollar out and put it in your pocket, and you ask the spectator how many coins are left in your hand? One. No, always two. You open your hand to show the two coins.
You start again, this time removing the penny. But in the same way, you always end up with two coins.
You do it again with the half dollar and the penny and it's still two coins.
In the end, you won't have anything left. The coins will be gone!!!
Very easy.
No techniques.
Automatic.