Innumeracy

[dr_tectonic]

We went up to Loveland this afternoon to visit Greg's friends Chris & Todd, and had a fine time. We went grabbed lunch/dinner at Red Robin, and we should have realized there would be trouble when our waiter couldn't count to five and thought there were only four of us.

Anyway, we had our dinner. The check comes, and we realize that everyone's order cost basically the same, so it's easy to split and we throw two credit cards at it.

Waiter comes back, sees the two cards. "So, you want to split this fifty-fifty?"

"Sixty-forty," I reply, "sixty on the gray card, forty on the purple one."

The waiter leaves. "He's not going to get it right," says Greg.

Sure enough, back he comes a few minutes later. "Did you mean sixty dollars on one and forty dollars on the other?" This is on a tab of 57 dollars.

So we explain that, no, we did not plan to leave a forty-three-dollar tip, but wanted 60 percent on one card and the rest on the other.

Now, I can see how my phrasing might confuse, and I would normally have said "36 dollars on one and 24 on the other", but he said "split it 50/50?", and I responded "split it 60/40". Is that so hard to follow?

Better yet: on the way home, we stopped at an Arby's to grab some drinks: small shake, small soda, large soda, small order of potato bites.

At the drive-through window, the guy hands us our drinks (after getting one of them wrong) and says "that'll be $19.21".

Um. Nineteen dollars? For three drinks and a small potato bite?

Eventually he gets it figured out -- they accidentally keyed it in with the previous order. It's nine dollars. Um, no, we say, that's still wrong. Oh, wait, it's seven dollars. Oh, and yes, here's the potato bites.

I don't fault order-taking-guy for hitting the wrong buttons, it happens, but it's kind of distressing that window-manning-guy seemed to have no sense whatsoever of roughly how much three drinks should cost...

Comments

[helava.livejournal.com]

Fast food is process. They're not trained to think about what they're doing, they're only trained to hit the buttons. If they were taught to think, they'd think, "man, this job sucks."

[thatwesguy.livejournal.com]

Nope. Just "nope."

Spend a day in my (high school math tutor) shoes, and you will discover to your dismay that back-of-the-envelope estimates you take *completely* for granted are not only not a part of the lives of most people under 25; the entire idea of back-of-the-envelope calculation is utterly missing from their entire worldview.

I kid you not.

I'm dead serious.

Truly.

[melted-snowball.livejournal.com]

Indeed, it's even absent from many math students at very good universities, sometimes. That, to me, can be quite shocking.

[ocschwar.livejournal.com]

Hate to say it, but that Wes guy speaks the truth.

(Tutored on CL. Saw for myself.)

[thatwesguy.livejournal.com]

Oh how I wish we were wrong.

On the bright side, I do occasionally -- very occasionally -- get a student who has a knack for mental calculation to use that skill for ballparking a calculator answer. To the student, it almost invariably feels like a magic trick, even when they thenselves perform it.

It's a bit spooky, actually.

But I'll keep at it.

And in the mean time, our powerful gnosis will shift inexorably into the perceptual realm of "black magic."

Which reminds me, come to think of it, of a science fiction short story in which the protagonist demonstrates the previously-unheard-of ability to calculate with pencil and paper, and in the end (spolier follows, I'm afraid)...



...the military decide to have him train others so that they can replace expensive missile-mounted computers with cheap humans.

But I digress.

[detailbear.livejournal.com]

And don't forget giving back correct change. Rarely can they make change in their heads; they have to read the screen. I'm old enough to remember when change was always counted back to you. The concept is totally foreign to most of them and is discouraged by most fast-food stores.

I confuse them when I give them $20.06 for a order of $9.56 to avoid getting pennies. And lately, I've had to correct a few who wanted to give me back the $8.91 order total instead of the $1.19 in change.

I remember in Grade 3 or 4 doing change problems in math class, memorizing 36/64 27/73 pairs that added to 100. *sigh*

[dcseain.livejournal.com]

I work with my friend nancylebov at cons with some frequency. People my parents' age are always a bit baffled that i know how to properly count back change. It's like the forget that i predate computers too, if not by as much as they do.

[thatwesguy.livejournal.com]

There's a great Dilbert (that I just failed to find) in which Dilbert hands the cashier some amount of cash for a purchase whose difference from the required amount is renderable in relatively large bills and quarters only, but in the case at hand, the subtraction problem is non-trivial. Like $23.61 for an $8.36 purchase. I wish I'd had it handy, because it's the closest I've come in recent memory to being on the other side of that transaction.

Even so, though, I had to work pretty hard to come up with an example where the answer seemed at least a little non-trivial, and even so, it isn't clear to me that it is.

Hurm.

[navrins]

I recently bought $43 in gas (ignore for the moment how scary *that* thought is) and gave the attendant three $20 bills.

He carefully counted out a $5 and three $1's and handed them to me, and began to walk away.

"Um, no," I said.

He turned back, said, "Oh, yeah, right," and handed me a $20, and began to walk away.

"Um, no," I said, perhaps a little more quietly. It took him a little longer to realize perhaps there was still a mistake in progress, and I started deciding whether to let him know (I don't consider it my job to look out for innumerate gas station attendants). Fortunately, I suppose, he figured it out again, came back, and got it right. But still... three tries? And handing me a $20 as *change*??

[ciddyguy.livejournal.com]

This is more common than you'd like to think unfortunately.

Even I sometimes have had problems when the total was say, $3.96 and the guy me a fiver but at the last minutes gives and adds the 4 cents, which should click in my head as exactly $2 back in change and this comes after I've already had the correct change in hand too.

We have an old fashioned style hamburger chain here in Seattle and while they now have newer electronic terminals, they are still required to figure out the change to give back, a rare case I know.

[zalena.livejournal.com]

Well, you were in Loveland, (she says from Squaresville) which we like to think is even squarer than Sqaresville. I mean, it's like WELD or LARIMER county out there, which means you are finally getting some distance from the BOULDER people, but apparently comes with its own set of baggage.

However, I doubt this explains math skills, though it might explain the amount of hot boys in large trucks, or women wearing floral patterns.

[dcseain.livejournal.com]

As one of my friends always says, The cost of innumeracy is incalculable., an understatement if ever i heard one. I think your percentile response to his was perfectly clear, he was just bloody clueless.

[thedragonweaver.livejournal.com]

At Borders I became known as the person to go to if there were any math-related questions. The one time it got really headachy was when this one lady was convinced her purchase— with teacher discount*— was wrong. She WAS right— to the tune of about $1.85 on a purchase of over $100. I think working it through took me almost half an hour... but hey, it was a weekday, I had nothing better to do.

*Teacher discounts do not work on all books, particularly one type with a tiny margin. Thankfully she hadn't left the store so I could check the codes on all the books.

[thedragonweaver.livejournal.com]

I should mention that the concept of innumeracy has been brought up in various circles. The idea is that a lot of people don't have a "feel" for math. (This is one of the disadvantages of digital learning over analog— sure, you can still count, but you don't get the feel of one hundred wooden blocks.)

This comes up, as you might expect, in statistics, particularly death statistics. People don't realize that if they say, for example, that 100,000 kids dying of drunk driving crashes in California every year might, you know, be kind of noticeable. And so a silly statistic slips into the mainstream conciousness, when somebody just made a transcription error and the real number is orders of magnitude lower.

Two examples— Robert Heinlein went to visit the Soviet Union sometime in the 1970s. When he was in Moscow, he took note of the people on the street and came up with an average population that was orders of magnitude lower than was claimed. When he got back to the US, he talked with a military planner friend about that and asked what he thought of the manner— and that friend came up with the same statistic as Heinlein, based on the infrastructure. (A higher population— or the amount that was claimed— would soon run out of essential services given the available roads and rivers.) Nobody challenged the stats coming out of Moscow because nobody stopped to think that the numbers were ridiculous.

And I had the most incredibly difficult time convincing an engineering student that Mariah Carey's voice could NOT be eight octaves. See, aside from the fact that Julie Andrews (pre-throat surgery) could hit four and change, and that was pretty much the biggest living range, to take your voice up an octave, you have to make your vocal cords twice as tight. So to sing eight octaves, your voice would have to be 2^8 times as tight at the end— that's 256 times as much stress. The human body just isn't designed for that... or at least, not that part.

[dr-tectonic.livejournal.com]

Numeracy is like literacy: it's definitely a learned skill, and you can be innately good or bad at at it. I have met (tutored!) people whose brains just didn't do math well.

It's even worse with probability and exponential growth. At least with regular arithmatic, we have instincts that work reasonably well if exercised. The human brain is just not wired well for handling probability and exponentials in a natural way. You have to do a lot of rearranging to invoke the right systems.

[thatwesguy.livejournal.com]

Hm. I'm not sure I entirely agree with this assertion.

Then again, I'm not sure I don't.

I will concede that exponentials and probability are both weird (the former in the sense of "unlike anything else you've experienced" and the latter in the sense of "counter to intuition in significant ways") but I feel like I have a pretty good intuitive feel for both.

Then again, I may be massively underweighting the amount of rearranging I did to get here.

Hm.

Interesting!

[earthling177.livejournal.com]

Hm... I will give you that Mariah Carey's voice is probably far from perfect. But what we heard in the late 70's/early 80's (when the film version of Hair came out) was that at that time Irene Cara (sp?) had the best voice/broadest range/most octaves. I dunno how many. Just that she could sing more octaves than anyone at that time. Not that it matters much (to me anyway), but I figured you might have heard of that too and we might end up (or I might end up) knowing a little more in the end, for example, were they wrong when they said that, or is it just that no matter what people like Barbra Streisand and/or Julie Andrews better anyway? All I remember is that at that time I thought that Irene Cara's cover of Hair was way cool. Come to think of it, I may be making a fool out of myself, I'm not even sure Irene Cara is actually the person who sings Aquarius. :-/

numeracy and rote

[boat-of-car.livejournal.com]

hmm...

Yes, I think for sure making change is a lost art: I just don't think it's being taught, and young skulls full o' mush aren't being exposed to the rod of arithmetic in quite the same way. And it's even more obvious the older I get, partly becuase I'm more experienced myself, but also, I think, because those who are *teaching* math are less-inclined to teach those skills, or don't have them themselves...



I consider myself to not be 'good at math', and yet I find I am able to do seat-of-my pants calculation much more quickly than most ( and it works out fine, as long as I rememebr to do an occasional reality check) it might be a learned skill for me, though- making change was one of those things like long division, balancing a checkbook and paralell parking that my parent's took alot of time making sure I knew how to do (I still remember spending several months at a tv tray in the kitchen doing long division as a 10(?) year old, and my father made paralell parking into a *science* which I had to master before getting the keys to the old toyota) When I was a carpenter, I can also remember being able to free-hand jobs that took most cabinet makers pencil and paper to do. But, there again- I come from a family of engineers and fixit men: I must have picked up the instinct, the same way you learn how to fish...