So I'm at a major retailer today. Begins with 'W'. My cashier is late teens / early twenties. My purchase totaled $8.86. Throwing off cashier to begin with, I pull out cash. Not a debit card. Initially, I offer a twenty - which the cashier rings through. But them I find I had $9.00 and offer that instead. So instead of the register telling him out how much change to give back, he's forced to do the math.
*He pulls out his phone and opens the calculator to figure it out.*
Now here in Canada, we've gotten rid of the penny, so we need to round up / down - but even I, rotten in math since I was a kid - told him he owed me 15ยข. He checked his calculator, looked at me like I had just spouted magic, and gave me the change.
Wow. Just wow.