In order to track the $500 loss limit in Missouri, all money must be accounted for.

So if you want to play one nickel in a machine, you would have to go to a cashier trade in a real nickel for a 5 cent token so you can play the machine. They would substract the 5 cents from your $500 loss limit (via the slot club card) and away you would go.

You have got to love states with loss limits.