When I was in high school I accepted a job as a clerk at a souvenir shop on the beach in northern Fort Lauderdale. I loved that job, and kept it for many years while I completed school. I recall that one of the first things I learned was how to calculate and count back change for customers. It seems like a simple thing - just count up from the amount of the sale until you reach the number of the bill you were handed - then count it back in the same way to the customer, so they can rest assured that they were handed the correct change.
I am constantly saddened that today people who are more than twice the age that I was then cannot perform this simple task. They simply punch in the amount they were handed, and the register calculates the change, and even drops the coins automatically. All they have to do is hand you the money, without a word about how the change was calculated, nor whether it is correct or not. We all just assume that since the register calculated it, it must be correct.
Our reliance on technology has now risen to even greater heights. I have read several stories recently (like this one from the Wall Street Journal) about GPS systems and online mapping software sending people to the wrong place, or even into on-coming traffic, and yet they simply blindly follow the directions. We assume it to be correct.
I had a personal experience with this recently. I had to attend a funeral at a chapel that I had not been to, so I turned to Yahoo! maps to locate the address for me. While I had not been to this particular chapel, I also knew immediately that the directions were completely wrong - it would have sent me 20 blocks to the north of where I should have been. So, I turned to Google maps instead - with the same result. In the end, I just had to locate the address myself, using good old navigation techniques based on my knowledge of the area.
The sad thing is that I would bet that many of the cashiers today would not know how to calculate or count back change if their register made a mistake or stopped working. We simply put too much trust in our technical devices, and don't think twice about following its advice - even when Mapquest sends us to someone's driveway instead of the county courthouse, or up a mountain side to a dead-end instead of reconnecting us to the highway.
Somehow, we need to bring common sense back into the mix when dealing with technology. After all, no matter how good technology becomes, it is still based on human input.