Cash registers are a staple in retail stores, restaurants and just about anyplace else that sells a product. Some cash registers have only a number pad and a few other buttons, while other registers have more than 50 different keys. It’s easy to make mistakes when using a register, especially when you first start out, but you can limit your mistakes by learning each key’s placement and function.

Learn the sign-in procedure. If you work on a register used by several different cashiers, then you probably will need to sign in each time you use the register. Some machines have a “Sign in” button, while others simply ask you to enter your cashier number to sign in.

Familiarize yourself with the register keys. Most cash registers have categorized buttons. For example, if you work at a pizza shop that offers a variety of Italian food, the register will typically have sections for pizza, calzones, salads and pasta. Sometimes each category is color-coded, but other times they are just grouped together on different areas of the keypad. If you work at a retail store, familiarize yourself with the number keys, “Total” button, “Tax exempt” button and other keypad functions that you regularly use.

Use only one finger. It may be faster to use two hands, but you’re more apt to make mistakes. A cash register isn’t like a keyboard: Pressing the buttons isn’t as smooth and errors aren’t as easy to correct.

Ask the manager or consult the register manual when you don't know how to charge an item. Many customers use debit and credit cards to purchase items, and each cash register is different when it comes to using cards. For example, some stores use cash registers with a built-in card reader, while other stores have an external card reader. Registers with a built-in card reader automatically ring up the purchase as a charge, but you have to manually ring in the purchase as a charge for registers with external card readers. You can simply press the “Cash out” button on some registers, while on others you have to press a “Charge” button.

Learn how to void an item. You’re going to make mistakes on the cash register occasionally, no matter how careful you are, so it’s important to learn how to quickly correct those mistakes. If you accidentally ring in an incorrect item, or ring an item twice, you can void the incorrect item or the total price.