When Given Cash, Register doesn't show Change to give to Customer!

[Nebula]

When Given Cash from a customer the Register doesn't show Change to give to Customer.
I don't seem to understand if I can see how much they are handing me some where in the interface or the register should show the exchange every time or maybe they are not giving me enough I am not really sure.

Has anyone had this happen and if the register doesn't show what the customers return amount should be how do i figure this out?

[Willow Rivers]

It does show you the amount you need to give. When you give the amount needed the number changes to green.

Lot of the times the customer will give you exact amount and no change is needed to be given. If you see a green $0.00 then just hit space bar to complete transaction.

[resonance]

Silly question, but are you looking at the proper screen? The screen in front just shows what they bought and the total. The screen on the right (above the cash drawer) will show the total, what cash they gave and the change needed as well as what you have counted out already. If they gave exact change, then it will say change needed as $0.00.