You spend an hour carefully selecting groceries based on the weekly sale tags. You arrive at the register, pay the bill, and walk out to your car. If you do not check the printed receipt before you leave the parking lot, you will likely lose money. Supermarket registers are not infallible. The digital systems powering the checkout lanes process thousands of transactions an hour. Glitches and data entry mistakes happen constantly. Paying attention to the screen protects your wallet from silent overcharges. Here is why pricing errors are more common than you think.
