Counting change back to the customer is a dying art, but a skill that can prove essential if your store loses power or you have a cash register malfunction. Being able to properly count back change can also provide an added customer service -- you can assure the customer that you have given him the correct change. The example used here counts back change to the customer if the total is $13.39 and the customer gives you $20.
Say the original amount to the customer before counting back the change ($13.39).
Start by counting back the lowest denomination. Work up from pennies all the way to quarters. So if 39 cents is due, one penny is "40," one dime is "50" and two quarters is "14."
Count back the bills starting with the smallest denomination and working up to the largest denomination. One dollar is "15" and one five dollar bill is "20." The final count should always be what the customer gave you.