I grew up in the days when during basic math class, they taught us to make change. In other words, if someone had to pay $7.75, and handed you a $10 bill, when giving them change you would start with what they paid and count it back to them. Out loud to prove you were doing it right. Like this:
Start with "$7.75" (say it out loud), add a quarter and say "$8.00" (because 7.75 + .25 = 8), add a dollar and say "$9.00", and another dollar and say "$10.00". There. Change given and everyone knew it was correct.
My first job was at JCPenney. Back then, a lot of people still paid cash for things, so I used that method a lot. On those occasions where someone paid with a credit card, we would have to make an imprint of the card with that little slidey machine, then we would have to pick up the phone and call the credit department to get an authorization number for the transaction. It took anywhere from 3-10 minutes to check someone out! And it was the norm. And if they paid by check? We had to make sure their phone number was on the check AND we had to write their driver's license number on it. Seriously, when was the last time you even had to show your ID to use your credit or debit card? (Okay, that did happen to me the other day, but it's not very often.)
If you can relate to the old way of counting change, you might appreciate this experience:
I was at the cash register at a fast food joint. I don't eat fast food. But I do occasionally enjoy a milkshake. *clearing my throat*
"That'll be $12.23."
I hand him a $20 bill and a quarter. Because I already have a wallet full of change and don't need any more.
"Okay here's $7.99, your order will be right up." He handed me a pile of change.
*blink, blink* "Um, I gave you a quarter, right? $20 and a quarter."
"Yes, I punched that into the register and it told me $7.99 change." He was pleased with himself.
*blink, blink* "It was $12.23, right? And I gave you 25 cents to cover that 23. So why do I have so much change?"
"Hmmm, that's a good question." Face turning red while he studies the receipt.
When I can stand it no longer I reach over the counter and point. "See here? You entered $20.22, not $20.25. The change should have been $8.02."
Panic ensues as his brain cannot keep up with my math. "Oh, right. It's been a long day." Nervous laugh as he has the manager open the till again.
"Okay, $8.03, right?"
"Oh, I mean $8.02. Here you go, those shakes will be right up."
Now to be clear, I don't blame the kid. He's never been taught any other way. It's just one of those moments where I get scared at our dependence on computers to do our thinking for us!