Another topic (The price of squash) made me think about something else. I don't check my receipts from stores, but I do know if it's grossly out of whack, but I do always count my change and I do it the "old fashioned" way ... backwards.
You know, total comes to $54.28 and you hand the cashier $100. I look at my change and count that as $55, then I count the bills upwards until I get to $100.
This is the way I was taught when I was a grocery store cashier in the days before registers told the cashier how much change to dispense. It comes in handy for those times when you make cash purchases at places that don't have registers. But I still do it at regular registers because while I trust the register to do math, I need to know that the math had the right formula to begin with ... IOW did the cashier enter the correct sum that I handed her which will determine the amount of change to dispense. And I have found errors like this, cashier entered $10 instead of the $20 that I handed her.
But so many youngsters today don't have this skill, and don't even know it exists. Some cashiers look at me like I have horns coming out of my head when they see me count the change again.