Cash registers are used in a variety of businesses, including grocery stores, restaurants, retail chains and mall outlets. A cash register is a machine that an employee uses to ring in customer selections, take payment and complete a sale. The buttons on a cash register vary, depending on the make and model, but basic registers carry common features.


All cash registers have number buttons, usually for the digits one through 10. The number keys are used to input quantities, prices and special codes particular to specific register functions that were set by the business or owner. Some registers may have digits higher than ten, depending on the type of business the register is being used for.

Math Functions

A register typically has math function buttons, such as percentage, addition and subtraction. The percent key is used to calculate merchandise discounts or in situations where percentages are needed, such as currency exchanges. A multiplication button may serve for quantity purchases; the cashier may press the correct number and multiplication buttons to calculate the price for the purchase of more than one of the same item.

Total and Tax

The total button is used to calculate the total cost of the purchase. Some registers have subtotal buttons that can be pressed to give the customer the cost of the items currently rung up or before tax is added. A tax button that is preset to the correct tax rate may be used to add sales tax to an order, but if the machine does not have one, the cashier may manually calculate the tax using the percent button.

Cash or Tender

The cash or tender button is used to input the customer's payment and typically opens the till, or drawer under the keys where the money is kept. The cashier is then shown the correct change on the register screen. A more advanced model may have a button for credit if a credit card swipe is attached to the register, but older models generally do not. Some businesses use separate credit swipe machines and enter the credit charge amount as cash or tender on an older register.

Void and Feed

Cash registers commonly have a void button that allows a cashier to delete a tally for a sale or just selected items. Some registers require a turn of a key inserted into the register to use the void button. A feed, or paper feed, button is used to draw the receipt paper into the proper place on the register when the roll or tape has been changed.