At the ATMs I’ve seen in the United States, when you ask to withdraw money, they ask you how much and tell you it must be in multiples of the smallest value bills it stocks. For example, if the machine has only 20 USD notes, it will say “enter your withdrawal amount in a multiple of 20.”
For some reason, the interfaces allow you to enter amounts that are completely impossible. In a machine that requires multiples of, say 10 USD, you can put in 5 dollars and 57 cents and the machine then rejects it and you have to restart the entire transaction, including entering your PIN.
The method of entering the value is like a digital microwave: 200 USD is entered as “2 0 0 0 0 <enter>”. More useful interfaces would be to:
- Enter the dollar amount, so “2 0 0 <enter>” for 200 USD
- Key in the number of bills, so entering “1 0 <enter>” would display “10 bills × 20 USD each = 200 USD total”.
- Press <plus> and <minus> buttons to choose the number of bills, so push <plus> ten times for 200 USD.
I request Diebold and NCR and the rest consider this as an improvement to their software.