At the point of sale, the merchant would calculate the amount owed by the customer and indicate the amount, and may prepare an invoice for the customer (which may be a cash register printout), and indicate the options for the customer to make payment.
Performing push-ups works a variety of muscles in your upper body, including specific muscles within your abdomen, chest, shoulders and upper arms. You can vary your technique by placing your hands at different widths to emphasize one area over another.
This is why. One of the most underrated benefits of doing push ups is the stretch it provides to your biceps and back muscles. As you lower yourself to the floor, your back muscles are effectively stretched, and as you push yourself to the starting position your biceps obtain a full stretch.