Subtraction is the cruelest math

I just got back from a trip to the local Office Depot to buy some CD-Rs so I can back up data for the upcoming move. The total came to $8.60. I handed the cashier a $20 bill. What followed was one of the more entertaining checkout scenes I have ever witnessed. I was being attended by a trainee, although an experienced employee was supervising her. The trainee accidentally hit the “enter” button on the register instead of the “$20” button, and so the register assumed I had paid the exact amount, and did not compute the change. The supervisor knew exactly what to do: “Just give him the change. It’s $14.40.”

Those of you playing along at home will realize, as did the trainee, that her math was a little suspect. “No, I think it’s $13.40,” she said. The supervisor got a calculator. Not believing its answer, she got out a piece of paper and pencil. Finally, after the calculator had given the same answer about three times, they decided to accept its wisdom, and the trainee counted out $11.60. At this point, they had to call over the manager to re-open the cash drawer so they could exchange one of the quarters for a nickel.

I shudder to think what would have happened were there long division involved.