Basic Math. Very Basic Math.

[Broomjockey]

...I told ya I was bad at math.

Hey, I'll trade you 10 of my shiny dimes for 8 of your quarters! You're coming out better 'cause you get two more!

[nomorecarts]

I'll give you 11 shiny pennies for those 8 quarters. you're even better off, because you get 11

[Difdi]

She ended up getting the change she was due and not what she was demanding, but the kicker (and there's always a kicker) was that she stated after our little exchange that she was a front end supervisor and trained her cashiers not to follow the cash registers' instructions.

Oh wow, I'd love to be a fly on the wall of that audit...

[SpyOne]

However, yeah, there are people out there who are physically incapable of doing what seems to most people to be simple no-brainer type calculations. 6% of the population (and that's more people that it sounds like) are incapable of doing simple calculations. So please don't dismiss someone out of hand as stupid if they can't do a "simple" math problem. They might have weird wiring in their heads. And believe me, they are acutely aware of how dumb people think they are because of it.

I do get that some people have learning disabilities. I have a problem learning foreign languages that I believe may be organic in nature.
I am surprised to learn that the percentage of the poplulation who are unable to learn how to do simple calculations is so high, but it is still FAR lower than my experience.
That is, if 1 in 20 people who come through my register has a such a disability, then about 1 in 10 of the people in my line have a good excuse.

If you are blind, you will get special help to deal with things that normally require you to see. But if you simply refuse to open your eyes, all you deserve is a quick rap on the head.



Back to the original topic:
This is an outlook that might help (combined with a lot of patience): if you are right, any other person can come up with the same answer, given enough time.
Fast-change artists are trying to confuse their target into agreeing with them, even though what they are saying is wrong. "It came to 17.52 and I gave you a 20, and then I gave you 17 cents, so you owe me 4.50, see?" A fast change artist will NOT shut up, step back, and wait for you to come to the same conclusion that he just did. So, by stepping back and shutting up, you are helping to defuse the concern that you are a fast change artist.
Also, they just might be able to come up with the right answer if given just a moment when you aren't talking to them.

If you are right, then they will come to the same answer as you on their own, and you don't need to brow-beat them into agreeing with you. And if you stop trying to brow-beat them into agreeing with you, they just might decide to trust your answer and not bother working it all the way out.
Once you have accepted that you will NOT be able to brow-beat them into agreeing with you, you will realize that your continued attempts to explain it to them can't speed up your transaction: you'll be done here when the cashier has figured out what the right answer is on his own. The only way you might speed things up is to change the amount you gave him to one where you both agree the math is simpler, and the correct answer will be reached sooner. Or loan him a calculator.

I try to follow that. It uses most of my "zen". I think that if I ran into that cashier from fast food you described (can't see that 20.25 - 5.25 = 15.00, and takes more than five minutes working it out), I just might do something very rude, unkind, and unhelpful in public.

[SpyOne]

I suppose here would be where I could explain my user name.

My coworker (D) was ringing out a lady (we'll call her F) and the total came to $10.99. Said lady tendered a $20. D entered the 20 into the register and the display changed to the change amount of $9.01. And, then, the unthinkable happened.

F: I have the penny.
D: Huh?
F: I have a penny, so you can give me a ten dollar bill.

This is exactly the kind of thing a quick change artist will do. It has all the flags: it almost makes sense, it involves handing money to the cashier after the amount tnedered has been keyed in, so the cahsiner can't rely on the computer to answer the question.

And if it worked, she'd have made a dollar right there (well, 98 cents). More importantly, she'd a have spotted a cashier who could be targeted for larger amounts using the same trick, possibly by other people.
Scam somebody out of 5 dollars 10 times a day, and you make a living.

[Jay 2K Winger]

God, this reminds me of something.

I went to the Mercersburg Academy for a year, and while I was there, the drama department and its students (including me) were invited to come up to New York City to attend a taping of "Who Wants To Be A Millionaire?" as exec producer or whomever was a graduate of the Academy.

This guy is in the chair and is four questions deep, still with all three of his lifelines. The question is something like

"This gas makes up the majority of Earth's atmosphere."
(A) Carbon Dioxide (B) Oxygen
(C) Hydrogen (D) Nitrogen

Now, I was a bit of a science geek as a kid, and I knew the correct answer is D. So did most of my classmates with me. The guy in the chair didn't have a clue. Even said, "Well, I know it's not B or D."

So he opts to use the Ask The Audience lifeline. We all pick up our voting pads, and the OVERWHELMING majority of the answers were for B or D. But he's still not sure. So he uses his Phone A Friend lifeline, calls up his friend who's a science teacher.

Contestant: "Hey, [name], the question is 'This gas makes up the majority of Earth's atmosphere.' A, Carbon Dioxide, B, Oxygen, C, Hydrogen, D, Nitrogen."
Friend: "Well, it's not B or D."
J2K:

But even the guy's science teacher buddy couldn't help him. He still wasn't sure. So he went with his 50/50 Lifeline. You get three guesses to guess which two options were removed, but the first two don't count.

Yup, options A and C were dropped, leaving him with B and D, the two answers that his buddy said weren't the answer.

Crowd: "Ooh."
Regis: "...where did you say this guy teaches again?"
Crowd:

Well, the guy decided to quit, and the answer was revealed as being D, Nitrogen. The man is thanked for his time, he leaves, and then another cool moment happens.

While they reset for the "fastest fingers" round, Regis looks over toward our group and looks at my classmate John.

Regis: "Did you know the answer, kid?"
John: "Of course."
Regis: "...smart ass."

For the rest of the taping, whenever Regis flubbed a line or something, he'd shout, "It's the kid's fault!" and was blaming John for his mistakes.

We got to meet him after the taping. He was pretty cool.

[Heatherina]

I equally suck at math--I shift into panic mode when asked to do math quickly or on the fly. I'm usually too worried that I'll mess up and say something stupid, that I do end up messing up and looking quite stupid.

[Primer]

I'll give you 11 shiny pennies for those 8 quarters. you're even better off, because you get 11

I'll give you my 8 shiny quarters for your 11 shiny pennies ONLY if your pennies have Indian heads on them.

[joetheman]

*customer sees item ring up for 40 cents*

C: Those are supposed to be 5 for $2.
Me: They are.
C: No they aren't, they're 40 cents each.

*facepalm*

They actually did get it then, thankfully they weren't stubborn enough for me to find a calculator and use it.

Also people don't realize there's tax on things, because most groceries don't have tax. Some guy had a 5 dollar bill and bought a sandwich and it's like 5.55 because of the stupid 11% tax on "prepared" food we have

guy: that's supposed to be 4.99
me: there's tax on it because it's prepared
guy: well I only got a 5 thank you for wasting my time *leaves the sandwich and walks off*