I just read that same study described in the National Research Council book I'm plowing through....

-- CatherineJohnson - 19 Jul 2005

I got bags of change and bills. I played customer and had him count out to the ten and then up to the dollar, and to the bill that I gave him. We would then check it with subraction. He was amazed. We practiced it for weeks until he felt comfortable making change for me at any amount. The only problem is that he confused it one day at the store. I had to remind him that he had to use simple subraction then. The "change trick" is when you're making change for someone with money in hand. I just thought it was a skill he should have

I agree!

Well, back when I was a grocery clerk the day did come when the registers all broke down because the power was out. Fortunately, people still knew how to add and subtract so we pulled out pencils and papers and kept checking people out.

Hah!

That would have been no problem for me.

We had daily charts, posted in the break room, showing EXACTLY, down to the penny, how much our drawers were 'over' or 'under' each shift we worked.

I was always amazed that, as careful as I was, I was normally over or under a bit.

Mary, our manager, always came out perfect.

I don't know how she did it.

-- CatherineJohnson - 19 Jul 2005

Now where was it that I recently came across a study someone had done of street urchin vendors, somewhere, showing they could do much better in practice, when selling in the street, than in the school setting...?

Street Mathematics, they called it.

Ah, I found it. Thank goodness for punchy memorable phrases like that; without them, I'd be lost.

-- CarolynJohnston - 18 Jul 2005

Well, back when I was a grocery clerk the day did come when the registers all broke down because the power was out. Fortunately, people still knew how to add and subtract so we pulled out pencils and papers and kept checking people out.

In India, I noticed, the street vendors can do almost any calculation at lightning speed. Practice and necessity do it every time.

-- WichitaBoy - 18 Jul 2005

I call that the "change trick," which isn't a trick at all. I did the same thing with my son. I got bags of change and bills. I played customer and had him count out to the ten and then up to the dollar, and to the bill that I gave him. He was amazed. We practiced it for weeks until he felt comfortable making change for me at any amount. The only problem is that he confused it one day at the store. I had to remind him that he had to use simple subraction then. The "change trick" is when you're making change for someone with money in hand. I just thought it was a skill he should have.

It's for all the fast food workers when the register breaks down.

-- SusanS - 18 Jul 2005

But what the heck.

-- CatherineJohnson - 18 Jul 2005

I should probably erase that comment.

-- CatherineJohnson - 17 Jul 2005

That's what I like in life, a clerk who's stupid AND snippy.

-- CatherineJohnson - 17 Jul 2005

Mortifying change-making moment.

I was in Nyack, trying to buy a bottle of water, and the sum was something like $1.07.

I gave the clerk $1.27 (something like that) and she didn't have a clue what to do.

Unfortunately, I discovered I didn't have a clue what to do, either, since--speaking of ZERO working memory--I found I couldn't hold both numbers in my head (the price & what I'd given her).....AND I always made change, back when I was a grocery clerk, in front of the cash registerl

I counted up as I pulled change out of the drawer.

The clerk got all snippy about it.

-- CatherineJohnson - 17 Jul 2005

I bet you Ben had a working memory hole.

Temple says she has practically NO working memory, and I bet Ben just lost the thread by the time he got to Bernie's office.

(Temple's wrong about having no working memory, but she does have less than the rest of us.)

-- CatherineJohnson - 17 Jul 2005

I have no idea whether this would help, but I taught Temple how to count change over the telephone.

She had no real way to tell whether someone was shortchanging her or not, although she could tell whether an amount being returned was grossly off.

So I taught her to count the change the way clerks used to do it in stores, but counting up from the price of the item to the amount you gave.

I taught my Singapore Math kids how to do it, and Christopher, too.

It's one of those lost arts that I'm sure, without any formal evidence whatsoever, people should learn.

I call it 'lost knowledge.'

There's all kinds of stuff people use to know (like the different cuts of meat, for instance) that younger generations don't have a clue about.

I think most women today have only procedural knowledge of cooking.

My mom majored in home ec on college, and she understood cooking.

She knew why different things worked or didn't work.

-- CatherineJohnson - 17 Jul 2005

Ben vs. vending machine

Bernie and I were talking tonight, and he told me a story that worried me a bit.

Ben came to visit us at work the other day, and wanted to get a snack from the vending machine. So he went into his dad's office and asked for some money. Bernie gave him a few coins, and Ben went into the snack room, picked out what he wanted, and put his money into the machine; but he didn't have enough. So he came in and asked for more; but he couldn't tell Bernie how much more he needed. He didn't seem to have much sense of how much more he needed, either.

Well, it wouldn't be the first time we came across this sort of gap in his understanding. We have a sort of a family byword for these things, very much like Catherine and Ed's no-common-sense-y; we call Ben's gaps his Cognitive Holes. They are located in unexpected places -- they're generally about something, like handling coins, that you think is very easy by comparison with other things he can do, like long division. And they tend to be very big gaping holes in his knowledge, and at first they were very frightening. But we come across them less often now than we used to, and we've found that once we know they are there, we can remediate them pretty quickly.

So I thought this was another run-of-the-mill Cognitive Hole.

Well, you tackle these by filling them in. Ben and I were ready for a change from what we've been doing lately, anyway (introductory equations, solved by adding and subtracting). We've been doing them all week, and struggling, and we finally got a 'click' a couple of nights ago (those babies are practically audible, aren't they?), and last night when he took his section test he got a 100. So tonight, when it was math time, instead of doing algebra, I got out some coins.

I had 3 quarters, and a dime. "OK, you're at our work, and you want a snack, and these are the coins I have", I told him. "The snack you want costs 60 cents. Which coins do you take?"

He went for two of the three quarters, and the dime. Good. "How much do I get back from the machine?" I asked. Nothing: good.

"OK, your snack costs 40 cents". He goes for the two quarters: he tells me the machine returns a dime.

"The snack costs 80 cents." He takes all the coins, and tells me the machine returns 5 cents.

In short, he passed my common sense test with flying colors, and Math Time was fun and a breeze for once. So what the heck was happening the other day? In short, what part of this Cognitive Hole we think we've uncovered am I not mapping correctly?

Tomorrow, we try it a little differently; we'll simulate the precise problem we had the other day with the snack machine at work. I'll give him too little money, tell him the snack costs a certain amount, and get him to tell me how much more he needs.

There may in fact be no Cognitive Hole, this time, just some situational rigidity. This is the deal with smart people on the autism spectrum; sometimes they know what they need to know, they just stiffen up when it comes time to apply it in the real world.

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• Posted by: CarolynJohnston
• LogDate: Jul 17, 2005 @ 00:21

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