The cashier begins with the amount owed on the transaction and counts the change owed back to the customer one piece at a time, adding up to the amount originally tendered by the customer for the transaction to correctly count back change. Counting back change during cash transactions helps prevent mistakes in the cash drawer and improves customer service.
To learn from an example, imagine that a customer gives the cashier a $20 bill for an $8.42 purchase. First, the cashier collects the $20 bill and calculates the amount of change owed to the customer, which in this case is $11.58. The cashier says aloud to the customer, "The total is $8.42 out of $20," and counts back the change from the smallest denomination to the largest. Handing back three pennies, he says, "Eight dollars and 45 cents." Handing back a nickel next, he says, "Eight dollars and 50 cents." Next, handing back two quarters, he says, "nine dollars," and handing back a $1 bill, he says "10 dollars." Finally, handing back a $10 bill, he says, "20 dollars total." The process of counting back change allows either the customer or the cashier to correct any mistakes immediately, eliminating common errors such as mistaking a $20 bill for a $10 bill.