It's not just the illiteracy, it's the innumeracy!

[BEC]

The usual approach is to downsize the item, a little at a time, at the same price. Then "30% bigger!!" for twice the price. Candy bars...I watched through the years as a plain Hershey bar got a little smaller, then a little smaller. Then it went back to the original size but it was a dime instead of a nickel. And so on.

I trust most companies to behave ethically about as far as I can throw Jeff Bezos.

Best -- Terry

I remember going through this process—make it smaller, then go back up and raise the price—with the little chuck gliders and rubber-powered balsa airplanes from North Pacific (and probably Guillow as well). I wonder, with today's balsa prices, how much the little 5¢ Strato glider would be today, if it was as big as the first ones I remember....but I don't really want to know.

 

[modeltrains]

I wonder, with today's balsa prices, how much the little 5¢ Strato glider would be today, if it was as big as the first ones I remember....but I don't really want to know.

Well, we can certainly guarantee it would be more, and likely quite a bit more, and not merely because of inflation,

Balsa Wood Shortage Affecting Wind Turbine Production
16th November 2019
https://generator-news.com/2019/11/16/balsa-wood-shortage-affecting-wind-turbine-production/

Balsa wood, which is more often know to be used in surfboards, table tennis bats and model aircraft also happens to be a main component in the cord of wind turbine blades due to its properties of being strong and lightweight. Prices of the material have nearly doubled in the past year and the shortage of its supply threatens to cause a delay in windfarms developments over the next year.
Tobias Hahn, who is the chief executive of Diab Group, one of the top three suppliers of materials for turbine blades, has stated that the shortages seen in Balsa is one of the biggest shortages out of all the materials that are used in the turbines.
Balsa wood is mainly grown in Papua New Guinea, Indonesia and Ecuador. The produces in these countries are actually benefitting from the shortage as the increased prices are likely to keep rising.

 

[BEC]

Yes, that was part of what I was thinking about.

 

[KC3KNM]

There are three types of ‘Mericans. Those who can count and those who can’t.

Just like there are two types of people:

Those who can extrapolate from incomplete data.

 

[Blast it Tom!]

Or 10 types... those who understand binary, and those that don't...
(old joke is old...)

 

[katinthebox]

Innumeracy is just like illiteracy, except it's with numbers and not reading/writing.

Went to Taco Bell for some cheap takeout; two tacos, one bean burrito, no sides, no drinks. Bright-eyed cashier blithely says $10.24". whaaaAAAAAT?? for THREE cheap items?

She finally figured out that it was wrong, new total was $6+. Still sounded high. Looked at the receipt; no, I didn't want the SUPREME burrito, wanted the BEAN burrito.

Second gal, assistant manager I guess, came out to fix it. Apparently she couldn't figure the difference between the two items, so she just refunded me a supreme, then sold me the bean.

The calculator was a wonderful tool when it came out, but now the downside really shows its face. The first gal didn't even recognize that the price was about three times what it should have been, and the second apparently couldn't do that advanced math. You know....percentages. Not just the general public; even college students. In an attempt to generate some thinking, I asked a first-year chem student what 4x7 was. Poor gal just sat there. Dropped the course shortly thereafter. Some guys can't count past 10 unless they take off their shoes, and they're stumped past 20 unless they take everything else off.

And if anyone thinks that it's bad now, just wait until retailers figure out just how little consumers know about prices and money. You will see "Just 49 cents per can, or SAVE and get a dozen for just 7.50!!" in every possible anti-consumer advertisement. And as most transactions are electronic these days, people will toss the receipt into the trash, never knowing that the cashier charged $10 for the can of Coke HE'S drinking. And kept the change.

Best -- Terry

So here's the thing about that job...
You're staring at a touch screen console. It has buttons for various menu options, and you have to tap the ones that match a person's order... as you hear it.
You've been standing there, hearing all variants of x supreme and y with beans, for hours. You're likely doing your best not to be careless, but so many things rhyme with "...ito..s ...reme..." on the menu that you're making an assumption, based on what you can hear over the noise of the food being made behind you and the other customers present (and, in my personal experience, also over the sound of constant existential screams in place of your usual internal monologue).
What you don't have? An actual calculator. A chair. Permission to say anything but "Sorry," or "Let me get the manager" if anything goes wrong, even if the problem wasn't your fault. You certainly don't get any instruction on how to think critically about what you're doing unless a customer complains, and you're actively encouraged not to, for efficiency's sake.

You had a receipt in your hands before you questioned the second price. You paid without objecting to the wrong price, just like the person behind the register didn't question what the console said the items cost (and, if they honestly thought you said what they entered into the console, why would they question it?)

As a mechanical engineer with no college degree, as someone with dyscalculia, as someone who has stood behind that counter at 16 and been the object of "You see, honey, this is why you go to college" while someone else yelled at me to come back to the register instead of cleaning up the massive ice cream spill in every cashier's immediate path, let me tell you, sometimes, a human's last vestige of sanity at that job is ringing up a combo as separate orders or giving an ostensibly middle aged person a senior discount... but sometimes you just screw up despite your best efforts because you're halfway through a clopen, you've had three hours of sleep, and you've got a four hour break to look forward to between 2:00 and 6:00 PM before your next 5 hour shift starts (meticulously timed so you only get a single 15 minute break per shift).

Don't get too upset about this stuff. No cashier wants to screw up, no cashier wants their manager upset. The repercussions of that can easily go way beyond a writeup. I promise you, the vast majority of the time, something goes wrong due to a combination of being overworked, underpaid, sleep-deprived, and frequently regarded as about as human as the cash register.

 

[Bowman]

An old chestnut asks "Is it seven and six is twelve, or seven and six are twelve?" Of course, neither is correct; seven plus six equals thirteen.

You're talking about a horse right?

 

[Blast it Tom!]

So here's the thing about that job...
You're staring at a touch screen console. It has buttons for various menu options, and you have to tap the ones that match a person's order... as you hear it.
You've been standing there, hearing all variants of x supreme and y with beans, for hours. You're likely doing your best not to be careless, but so many things rhyme with "...ito..s ...reme..." on the menu that you're making an assumption, based on what you can hear over the noise of the food being made behind you and the other customers present (and, in my personal experience, also over the sound of constant existential screams in place of your usual internal monologue).
What you don't have? An actual calculator. A chair. Permission to say anything but "Sorry," or "Let me get the manager" if anything goes wrong, even if the problem wasn't your fault. You certainly don't get any instruction on how to think critically about what you're doing unless a customer complains, and you're actively encouraged not to, for efficiency's sake.

You had a receipt in your hands before you questioned the second price. You paid without objecting to the wrong price, just like the person behind the register didn't question what the console said the items cost (and, if they honestly thought you said what they entered into the console, why would they question it?)

As a mechanical engineer with no college degree, as someone with dyscalculia, as someone who has stood behind that counter at 16 and been the object of "You see, honey, this is why you go to college" while someone else yelled at me to come back to the register instead of cleaning up the massive ice cream spill in every cashier's immediate path, let me tell you, sometimes, a human's last vestige of sanity at that job is ringing up a combo as separate orders or giving an ostensibly middle aged person a senior discount... but sometimes you just screw up despite your best efforts because you're halfway through a clopen, you've had three hours of sleep, and you've got a four hour break to look forward to between 2:00 and 6:00 PM before your next 5 hour shift starts (meticulously timed so you only get a single 15 minute break per shift).

Don't get too upset about this stuff. No cashier wants to screw up, no cashier wants their manager upset. The repercussions of that can easily go way beyond a writeup. I promise you, the vast majority of the time, something goes wrong due to a combination of being overworked, underpaid, sleep-deprived, and frequently regarded as about as human as the cash register.

My wife worked for a time in retail at one of those POS systems (a double-entenre acronym if ever there was one), and she says she thinks the software developers used to have meetings to see if they could make the various menus more complicated and obtuse. I always give a cashier the benefit of the doubt.

We almost never go to fast food with out some sort of coupon, which adds to the poor soul's misery. Once, when a new one had a particularly devilish time with our discounts, she asked for a name for the order - I couldn't resist - "Beauregard"! The crestfallen look on her face was priceless! And immediately I said, "Naw, it's Tom", and thanked her for her time and for working through it, and assured her she'd pick it up and would do just fine.

 

[katinthebox]

My wife worked for a time in retail at one of those POS systems (a double-entenre acronym if ever there was one), and she says she thinks the software developers used to have meetings to see if they could make the various menus more complicated and obtuse. I always give a cashier the benefit of the doubt.

We almost never go to fast food with out some sort of coupon, which adds to the poor soul's misery. Once, when a new one had a particularly devilish time with our discounts, she asked for a name for the order - I couldn't resist - "Beauregard"! The crestfallen look on her face was priceless! And immediately I said, "Naw, it's Tom", and thanked her for her time and for working through it, and assured her she's pick it up and would do just fine.

Oh lord I forgot about the damn coupons.
The worst was "OK but instead of (normal ingredient) can I get (wtf why would you want this but I can't say no) instead?" OH GOODY LET ME NAVIGATE THE SUBSTITUTIONS.
There's a reason my "SUB BF TO BL BN" Taco Bell order so frequently gets rung up as "-BF + BL BN" to the tune of an extra $0.75 or whatever, and it's because that kind of thing is as counterintuitively included in the UI as possible.
Fun story, one time I had a priest, collar and all, come through my line and manage to order a combination of random stuff that added up to $6.66 after tax. He immediately said "Oh, hmmm... how about an extra (thing I don't want even a little bit), too?"

 

[Ez2cDave]

Of course, the pandemic pretty much killed use of cash here in the states. I haven't used cash for a single purchase in 14 months.

In my "old school" world, "cash is king" . . .

I enjoy the anonymity and privacy of cash, a luxury that I know will, eventually, disappear.

Dave F.

 

[dhbarr]

So here's the thing about that job...
You're staring at a touch screen console. It has buttons for various menu options, and you have to tap the ones that match a person's order... as you hear it.
You've been standing there, hearing all variants of x supreme and y with beans, for hours. You're likely doing your best not to be careless, but so many things rhyme with "...ito..s ...reme..." on the menu that you're making an assumption, based on what you can hear over the noise of the food being made behind you and the other customers present (and, in my personal experience, also over the sound of constant existential screams in place of your usual internal monologue).
What you don't have? An actual calculator. A chair. Permission to say anything but "Sorry," or "Let me get the manager" if anything goes wrong, even if the problem wasn't your fault. You certainly don't get any instruction on how to think critically about what you're doing unless a customer complains, and you're actively encouraged not to, for efficiency's sake.

You had a receipt in your hands before you questioned the second price. You paid without objecting to the wrong price, just like the person behind the register didn't question what the console said the items cost (and, if they honestly thought you said what they entered into the console, why would they question it?)

As a mechanical engineer with no college degree, as someone with dyscalculia, as someone who has stood behind that counter at 16 and been the object of "You see, honey, this is why you go to college" while someone else yelled at me to come back to the register instead of cleaning up the massive ice cream spill in every cashier's immediate path, let me tell you, sometimes, a human's last vestige of sanity at that job is ringing up a combo as separate orders or giving an ostensibly middle aged person a senior discount... but sometimes you just screw up despite your best efforts because you're halfway through a clopen, you've had three hours of sleep, and you've got a four hour break to look forward to between 2:00 and 6:00 PM before your next 5 hour shift starts (meticulously timed so you only get a single 15 minute break per shift).

Don't get too upset about this stuff. No cashier wants to screw up, no cashier wants their manager upset. The repercussions of that can easily go way beyond a writeup. I promise you, the vast majority of the time, something goes wrong due to a combination of being overworked, underpaid, sleep-deprived, and frequently regarded as about as human as the cash register.

Woo, getting flashbacks to running the McD's drive thru on Saturdays. Wouldn't have been as hard except I worked 45 mins of my lunch hour at BK all week.

 

[Dipstick]

This thread sounds like half of the staffroom conversations at the school where I teach. Early exposure, ideally real world, is very helpful. I learned mental math under 50 pretty quickly selling veggies at the Farmer's Markets where my family sold veggies. It was very helpful! Playing banker in family board games is another great idea.

 

[katinthebox]

This thread sounds like half of the staffroom conversations at the school where I teach. Early exposure, ideally real world, is very helpful. I learned mental math under 50 pretty quickly selling veggies at the Farmer's Markets where my family sold veggies. It was very helpful! Playing banker in family board games is another great idea.

But when you're not asked to know rhe price of anything, just to push buttons, on the offchance someone pays cash, the register tells you how much change to give, and if under any other circumstances, you'd be allowed to use the actual calculator on your phone... Why should you be expected to be able to answer "Gal in your first day of college chemistry class, in front of everyone, what's 7*4?"
TBH, my alarm doesn't shut off until I do six arithmetic problems, I sit at a desk and STEM all day, and I unequivocally do not have it in me to include any unanticipated operators beyond + and - in my life... and even then, like I said, dyscalculia makes any math extremely stressful.

I promise you though, as a freshman in college, sitting in a chemistry class (assuming based on the description that this was likely a lecture, but if I'm wrong, consider what follows an understatement), the first thing on my mind was "Oh, wow, uh... that's a lot of Axe spray in this room," and the second thought was "Think before you speak if you're asked a question."

No wonder that young woman dropped the class. I don't want to pay around $500 to put myself through a semester of someone toying with me to tell internet stories, either.

 

[modeltrains]

And what comes to mind now is the Tumblr blog talesfromyourlocalcashier.
Yes, having been in and out of retail over a 23 year span I do follow it
But you have to be logged in to view it.

All kinds of stories there.
Some posts are family friendly some are not.
Some are uplifting and some express frustration or anger.

I will take the liberty of sharing this segment of one post,

• It’s pretty common for people to walk their dogs to the store, or have them in the car after a walk on the beach, and we all always lose our minds over them. The customers are always very proud of how cute their dogs are and happy to tell us all about them.
• Since the coronavirus pandemic started, a good deal of our regulars, especially the seniors, make a point every time they see us to ask how we’re doing, and to tell us to look after ourselves, as we do to them. We all feel genuine care for each other, which is something to be especially grateful for in these times.

 

[KC3KNM]

But when you're not asked to know rhe price of anything, just to push buttons, on the offchance someone pays cash, the register tells you how much change to give, and if under any other circumstances, you'd be allowed to use the actual calculator on your phone... Why should you be expected to be able to answer "Gal in your first day of college chemistry class, in front of everyone, what's 7*4?"
TBH, my alarm doesn't shut off until I do six arithmetic problems, I sit at a desk and STEM all day, and I unequivocally do not have it in me to include any unanticipated operators beyond + and - in my life... and even then, like I said, dyscalculia makes any math extremely stressful.

I promise you though, as a freshman in college, sitting in a chemistry class (assuming based on the description that this was likely a lecture, but if I'm wrong, consider what follows an understatement), the first thing on my mind was "Oh, wow, uh... that's a lot of Axe spray in this room," and the second thought was "Think before you speak if you're asked a question."

No wonder that young woman dropped the class. I don't want to pay around $500 to put myself through a semester of someone toying with me to tell internet stories, either.

I don't understand the push for mental math. Outside of very basic stuff I verify everything I do at work externally from myself. I'm a machinist and do very little manual math... most everything I'm working with I use a calculator as a fail safe. It's really rough when you're off by a couple thou on some manual math and scrap a part (or you're off by a lot and scrap a machine and maybe yourself ). I work nights and am always half asleep, so I err on the side of caution when possible.

Same for memorization. I keep notes and have references, leaning on memorization of any kind is just asking for you to misremember and open the door to mistakes.

 

[Dipstick]

I don't understand the push for mental math. Outside of very basic stuff I verify everything I do at work externally from myself. I'm a machinist and do very little manual math... most everything I'm working with I use a calculator as a fail safe. It's really rough when you're off by a couple thou on some manual math and scrap a part (or you're off by a lot and scrap a machine and maybe yourself ). I work nights and am always half asleep, so I err on the side of caution when possible.

Same for memorization. I keep notes and have references, leaning on memorization of any kind is just asking for you to misremember and open the door to mistakes.

And yet, the ability to do the mental math seems to add a critical ability to understand the result the calculator gives...I actually don't teach math and can't prove there is a verifiable link, but it sure seems like there is...

 

[KC3KNM]

And yet, the ability to do the mental math seems to add a critical ability to understand the result the calculator gives...I actually don't teach math and can't prove there is a verifiable link, but it sure seems like there is...

If you make the assumption that the person using the calculator has no idea what math is, sure I'd agree.

Personally, instead of putting in the time to be able to add 1.5936 to .0568 effortlessly, I'd rather focus on other skills. To each their own, I guess...

 

[Ronz Rocketz]

Here's a stumper that requires either a calculator or pencil and paper.

If watermelons cost $12 a dozen, how much are a 100 watermelons?

\[ f(n) = \int_0^\infty \mathrm{watermelon}\,\mathrm{d}watermelon *\frac{12}{dozen} *n |_{n=100} \]

 

[mbeels]

Personally, instead of putting in the time to be able to add 1.5936 to .0568 effortlessly, I'd rather focus on other skills. To each their own, I guess...

I think that the point is not to mentally add those two numbers to the nth digit, but to know that the answer should not be > 2.0, or < 1.0. If I enter that into my calculator and see something besides 1.6xxx, I expect I made an entry error.

 

[jqavins]

But when you're not asked to know rhe price of anything, just to push buttons, on the offchance someone pays cash, the register tells you how much change to give, and if under any other circumstances, you'd be allowed to use the actual calculator on your phone... Why should you be expected to be able to answer "Gal in your first day of college chemistry class, in front of everyone, what's 7*4?"
TBH, my alarm doesn't shut off until I do six arithmetic problems, I sit at a desk and STEM all day, and I unequivocally do not have it in me to include any unanticipated operators beyond + and - in my life... and even then, like I said, dyscalculia makes any math extremely stressful.

I promise you though, as a freshman in college, sitting in a chemistry class (assuming based on the description that this was likely a lecture, but if I'm wrong, consider what follows an understatement), the first thing on my mind was "Oh, wow, uh... that's a lot of Axe spray in this room," and the second thought was "Think before you speak if you're asked a question."

No wonder that young woman dropped the class. I don't want to pay around $500 to put myself through a semester of someone toying with me to tell internet stories, either.

I can only half agree. The half I agree with is that holding that young woman up to ridicule is both Not Cool and Not Helpful. The part I don't agree with is that it shouldn't be assumed she should be able to answer correctly. No one, in my opinion, should complete the sixth grade without having drilled the multiplatinum table and should know 4×7 immediately (unless there is some genuine disability involved).

If you make the assumption that the person using the calculator has no idea what math is, sure I'd agree.

Personally, instead of putting in the time to be able to add 1.5936 to .0568 effortlessly, I'd rather focus on other skills. To each their own, I guess...

I think that the point is not to mentally add those two numbers to the nth digit, but to know that the answer should not be > 2.0, or < 1.0. If I enter that into my calculator and see something besides 1.6xxx, I expect I made an entry error.

That and, if the calculator gives you an answer that makes no sense, like trying to take a 100 mil depth of cut, you know that's crazy, just as the student who claimed there were1.24×10^-17 atom is 13.3 g of sodium should have known. If you were just doing whatever the calculator tells you, as so many of "these damn kids today" do, then you'd be nothing more than a squishy, breathing CNC machine. Those machines are frightfully easy to misprogram, and you're not.

 

[prfesser]

But when you're not asked to know rhe price of anything, just to push buttons, on the offchance someone pays cash, the register tells you how much change to give, and if under any other circumstances, you'd be allowed to use the actual calculator on your phone... Why should you be expected to be able to answer "Gal in your first day of college chemistry class, in front of everyone, what's 7*4?"
TBH, my alarm doesn't shut off until I do six arithmetic problems, I sit at a desk and STEM all day, and I unequivocally do not have it in me to include any unanticipated operators beyond + and - in my life... and even then, like I said, dyscalculia makes any math extremely stressful.

I promise you though, as a freshman in college, sitting in a chemistry class (assuming based on the description that this was likely a lecture, but if I'm wrong, consider what follows an understatement), the first thing on my mind was "Oh, wow, uh... that's a lot of Axe spray in this room," and the second thought was "Think before you speak if you're asked a question."

No wonder that young woman dropped the class. I don't want to pay around $500 to put myself through a semester of someone toying with me to tell internet stories, either.

You appear to have inferred a few incorrect ideas.

1. I was not angry or upset with the cashier or the manager.
2. I was not angry or upset with fast-food workers and the industry.
3. I did not ask the question about 4*7 in front of the class.
4. I did not ask it on the first day, it was after the first exam.
5. I do not ask questions in order to toy with someone so I can have an internet story.

My point was--and I thought this was implied by the subject--- that this was yet another example of the (low) level of knowledge and life skills of the U.S. public. I see such examples literally every day, and based on responses in this thread, a lot of other people do as well.

It's probably true that the cashier didn't see the prices. Then, neither did I. All that was listed on the wall were specials and combos, no prices of individual items other than drinks and sides.

However...I'd have thought that anyone who has eaten at a fast food restaurant more than a few times would be aware of approximate prices, let alone someone who probably worked in fast food. Again, it's about a lack of life skills. I suppose I should be happy with that lack, as it suggests that others (not me) in the country will pay for that lack. Really pay, as in dollars and cents. This country takes advantage of those who lack knowledge of one sort or another; it's called advertising and marketing.

The gal in class was having trouble with understanding a particular concept. During problem sessions I set a few problems, then walk around the class for the next half-hour or so. I thought I was helping the student (one-on-one) grasp my explanation by setting an extremely simple "leading" problem that would direct her on how to think. I was mistaken to assume that it was an extremely simple example.

In many business classes (not accounting!) a sharp student rarely needs to pay close attention. I took five business courses way-back-when, along with two other chem majors. We all aced every exam in a junior-level marketing course (for which none of us had the formal prerequisites) and were always the first ones to finish the exam. But if a student is enrolled in (most) STEM curricula, he/she better be prepared to attend every class, pay close attention, do all the assigned homework when it's assigned. A student who can't do that has no business in a class that is instrumental to their career and upon which people's lives depend.

Finally...you seem to be implying that in university one pays money for a course and should expect some kind of special consideration. Like it or not, what one pays for is the opportunity. The result---success or failure---is the student's responsibility.

Best -- Terry

 

[jqavins]

You appear to have inferred a few incorrect ideas.
∙∙∙
3. I did not ask the question about 4*7 in front of the class.
∙∙∙

I confess I had that same mistaken impression. And that does make a big difference.

 

[KC3KNM]

I think that the point is not to mentally add those two numbers to the nth digit, but to know that the answer should not be > 2.0, or < 1.0. If I enter that into my calculator and see something besides 1.6xxx, I expect I made an entry error.

I get what you’re saying, but I think you’re misinterpreting what I mean. If we’re going to assume the person using the calculator doesn’t know what math is, I’d agree it’s a lost cause. If you use your loose mental math and see 1.6xxx you could very well be wrong and just take the answer as correct without caring to verify... it’s not difficult to look at both numbers when you put them into the calculator to make sure you got it right. Takes just about as much time to do the rough math in your head as it does to verify the numbers you’ve input are correct and you’re not making assumptions as with the mental math.

That and, if the calculator gives you an answer that makes no sense, like trying to take a 100 mil depth of cut, you know that's crazy, just as the student who claimed there were1.24×10^-17 atom is 13.3 g of sodium should have known. If you were just doing whatever the calculator tells you, as so many of "these damn kids today" do, then you'd be nothing more than a squishy, breathing CNC machine. Those machines are frightfully easy to misprogram, and you're not.

I’m not sure why a 100 mil DOC is crazy. Could you expand on this?

Also, could you point out where I stated “do whatever the calculator tells you to without question”? I do recall writing that I verify everything via external methods and I use a calculator on all math as a fail safe.

 

[jqavins]

I’m not sure why a 100 mil DOC is crazy. Could you expand on this?

My ignorance of machining is showing. I believed that a full tenth of an inch in a single pass was crazy; please pardon the mistake. The point is that you do recognize what's crazy and what's not (better than I do, obviously). Unlike the the student who reported that there is less than one atom in that 13.3 g despite the fact that the very word "atom" means there can't possibly be less than one, or the cahier who didn't blink at a $10.24 total for three cheap items at Taco Bell. (Heck, no one goes to Taco Bell except to get Mexicanish food cheap. )

Also, could you point out where I stated “do whatever the calculator tells you to without question”? I do recall writing that I verify everything via external methods and I use a calculator on all math as a fail safe.

First, I took "external methods" to be the calculator, and the statement seemed to say that you trust the external methods implicitly. The main subject of the thread is that the loss of basic math ability, including the ability to or habit of performing sanity checks of machines' results, seems to be greatly diminished in the general public in recent decades.

It now seems as if, perhaps, there's really less distance between our positions on this than I (or you? or Marten?) initially perceived.

 

[KC3KNM]

My ignorance of machining is showing. I believed that a full tenth of an inch in a single pass was crazy; please pardon the mistake. The point is that you do recognize what's crazy and what's not (better than I do, obviously). Unlike the the student who reported that there is less than one atom in that 13.3 g despite the fact that the very word "atom" means there can't possibly be less than one, or the cahier who didn't blink at a $10.24 total for three cheap items at Taco Bell. (Heck, no one goes to Taco Bell except to get Mexicanish food cheap. )
First, I took "external methods" to be the calculator, and the statement seemed to say that you trust the external methods implicitly. The main subject of the thread is that the loss of basic math ability, including the ability to or habit of performing sanity checks of machines' results, seems to be greatly diminished in the general public in recent decades.

It now seems as if, perhaps, there's really less distance between our positions on this than I (or you? or Marten?) initially perceived.

No worries, I get it. I was a bit confused, as a reasonable DOC is going to vary wildly based on material, tooling, fixturing, machine rigidity, etc... But I’d argue that understanding is based more on experience than just the numbers a calculator spits out. It doesn’t really matter how good at math you are if the SFM and chip loading you’re basing your calculations on is incorrect in this example.

I have a pretty solid workflow I follow that kind of error checks itself and I catch most mistakes before they’re an issue. I’d absolutely consider a calculator as part of my toolbox for making sure I’m not doing something dumb, but I also need to make sure I don’t put something dumb into the calculator.

I wasn’t very clear, but I was trying to say that if the choice comes down to doing some mental math and running with it or plugging it into a calculator to be absolutely sure, I’m going to go with the latter. I think the sanity checking ability extends past basic math in most cases, if you don’t know what you’re looking for in the first place the numbers start to become irrelevant.

While a math error from the cashier is always possible, it seems just as likely they might not know how to operate the POS and will come up with an incorrect order total. Though, I wouldn’t doubt that apathy plays a part. I do think the older folks harp on calculators and computers being the issue to an irrational degree when lack of focus or just flat out not caring seem to explain a lot of it. Something tells me kids were giving out incorrect change long before computers were a thing.

I don’t think we’re very far off from each other... I just struggle with clearly expressing what I mean, that’s my bad.

 

[R. S. Galileo]

In high school, (many years ago), I worked part time at McDonald's. This was before the cash registers that had buttons that read "Big Mac" and "Shake" printed on them. We had to memorize the item prices and add a long string of those numbers on the order pad. Since we were constantly doing this, we were pretty fast and accurate. I'm sure the kids of today could do the same thing, but for the over reliance on calulators. Simple use it or lose it.
I recently made a purchase that came to $9.14. Not wanting the change, I gave the cashier $10.14. She pushed the change back at me and said, (condescendingly, I thought), "the $10 is enough." Her cash register told her to give me 86¢, which she did. I added my 14¢ to the pile and politely requested a dollar bill. After a second, she obliged, but I wasn't sure if she had made the connection.
Finally, there's the famous true story from the 1980's. A & W tried to compete with McDonald's' Quarter Pounder by introducing their own one-third pound burger at a similar price point. It didn't sell and they scrapped it. Market research showed people thought they were being overcharged -- 3 is smaller than 4, after all -- and they thought themselves to be smart consumers.

 

[dr wogz]

and teh reports of a person asking for a half-dozen McNuggets..

"Sorry, sir, we don't' sell a half dozen. Your choices are 4, 6 or 10 pcs.."

 

[Antares JS]

Finally, there's the famous true story from the 1980's. A & W tried to compete with McDonald's' Quarter Pounder by introducing their own one-third pound burger at a similar price point. It didn't sell and they scrapped it. Market research showed people thought they were being overcharged - 3 is smaller than 4, after all, and they thought themselves to be smart consumers.

One of my best childhood big brain moments that was shocking enough that I still remember it:

We were doing fractions in 3rd grade math and the teacher drew two circles, and then drew lines dividing one into fifths and the other into sixths and, with that visual aid right in front of us, asked the class to vote on whether 1/5 or 1/6 was bigger. I was literally the only one who voted for 1/5. It was clearly larger in the visual aid right in front of us and when asked to explain why I voted like I did, I said it was clearly larger per the picture, as well as something to the effect of if you have one cookie and have to divide it equally among multiple people, it makes sense that the fewer people you have to share with, the bigger the pieces of cookie are going to be.

Regardless of being able to make the connection to the latter explanation, I couldn't believe the entire rest of the class couldn't recognize that 1/5 was bigger than 1/6 with that visual aid right in front of us.

 

[jqavins]

and teh reports of a person asking for a half-dozen McNuggets..

"Sorry, sir, we don't' sell a half dozen. Your choices are 4, 6 or 10 pcs.."

That one reminds me of the totally unrelated and probably untrue tale of the man who asked a waitress for coffee without cream. She replied "I'm sorry, we're out of cream, but you can have your coffee without milk."

 

[dr wogz]

That one reminds me of the totally unrelated and probably untrue tale of the man who asked a waitress for coffee without cream. She replied "I'm sorry, we're out of cream, but you can have your coffee without milk."

and I'm suddenly reminded of various lines from the movie 'Airplane'....