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You mean they don't now?
I'm pretty sure we did all our times tables in infant and middle school, and I remember doing long division and multiplication there too. (Though I forgot how to do long division by hand a long time ago.)
I'm also pretty sure my six year old is starting to do times tables at school to, though it's not taught parrot fashion like it used to be.

Well duh. Basic life skill.
If a big majority of children don't know most of them by 11 the school is failing.

It was compulsory when I was at school. We had to learn them and then recite them before the whole class and we got stars on a poster on the wall with our names. A lot of peer pressure to get you to know your times tables.

But if this is true, then it sort of explains that economics paper case this week. If the question has some fairly basic math in it, but math has detiriorated so much that they don't even know their times tables...

Times tables were done in Primary school although I don't recall going past the 10x table as there wasn't deemed to be any real need to go beyond that (what with SI units and currency decimalisation).
I may be remebering wrong but I don't think we did long division (if that's dividing by numbers greater than 10) until early in secondary school but it was linked up with doing things like solving polynomial equations as the principle we were taught was similar.

The only time I've ever done long division once I left school was to prove to myself (or someone else) I could still do it. By the time children of say 6 years today leave school, the amount of computing power they will have about their person would make us agog. The only time they won't have a device that's manifestly better at arithmetic than any human brain is when they're in the bath. And possibly not even then.

That is not to say that certain mathematical skills aren't 'life skills', they certainly are. You need to be able to do quick simple mental arithmetic all the time - how long until a bus arrives, how much change should I have been given, how much is a tip if we say 10% of the bill? that kind of stuff. But being able to do long division is a skill that's now as necessary as being able to thatch a roof.

We need to continually decide what skills our children are likely to need in their daily lives and teach them appropriately. Just because something was necessary to be learned when were kids doesn't mean it still is.

Jon

I knew multiplication tables up to 12x12 by the time I was 8. One of the clever clogs knew it up to 20x20 but he had just come from Pakistan. I'd argue being able to do mental arithmetic is important. I can still do long hand division but have no use for it.

And, if you don't know math, how do you know the results coming out of the computer are correct? There was a great scene in Darknet, the second Daniel Saurez book (Freedom(tm) in English?), where Peter Sebeck is in a fast food restaurant and has ordered two menus for around $9 and the cash register says he owes $15 or so. He keeps arguing with the kid at the cash register that §3.50 + $5.50 doesn't equal $15, but the kid refuses to believe him, because the cash register is telling him that the two menus cost $15... (approx. prices from memory, I don't have the book to hand)

I've used math a lot to double check that the programs I've written are giving the correct results. And it is well known that spreadsheets like Excel give wrong answers a lot, if there are a lot of decimal places involved due to rounding errors.

Then there was the Pentium bug.

If you can't do the math, how do you know you aren't being lied to?

When I go shopping, I often calculate the prices as I go and if the amount at the checkout is very different, then I'll double check the receipt before leaving the store.

I do long division several times a day checking applications and report files

So you've never trusted any data any device ever gives to you without manually checking it first? That includes every till receipt you've ever had, every phone call you've ever received, every email... You never take the lift in case it might dump you out at the wrong floor? You always have someone running alongside your car checking the speedo is correct?

We all rely every day on the thousands of fundamental calculations devices around us make. Every. Single. One. of us. Yes, in theory that is a bad thing that we can't replicate what machines do for us manually but the fact is the history of humanity has been the invention of devices that take boring, repetitive tasks away from us so we can spend our time doing better things.

If you don't trust a calculator you're not 'being careful', you're weird and you're wasting your time.


If your memory isn't perfect, how do you know your maths are?


Most people don't spend their daily lives worrying about things where many decimal places are an issue. Most people need to work to two decimal places in the main.


Fair enough. Hey, pity nobody made anything of it and thus it was never fixed eh?


I dunno, maybe I'm reasoning there's no actual value in a calculator lying to me.


How often has that happened? And when it has happened has it been a fault the machine or a fault of the operator (e.g. entering something twice)?

Please tell me you're not an engineer and you have nothing whatsoever to do with the design/manufacture of anything safety-critical.

I have never known the times tables up to the 12-times table. *shrug*

Mark

That isn't what I said. But when I run.a new program for the first time or I write a new piece of code, the first thing I do is make sure that the results it is giving are correct. It doesn't mean that I have to run next to my car every time I go out. But ensuring the speedo is correct is actually a legal requirement AFAIK.

For my motorbike test, my instructor kept telling me that I was riding too slow and we both rode at 30mph indicated on his bike. For the test, I tried that and it felt too fast, so I halved the difference between indicated 30mph and what he told me 30mph was. The examiner nearly failed me, but asked why. I told him that my instructor had told me that my speedo was running slow, but that his "30"mph felt too fast, so I had halved difference. He said I was still too fast, but it was borderline and he let it go. Turned out the instructor's bike was wrong, not mine.

Likewise, I usually test the RPM in the "right" gear for key speeds (30mph, 40mph, 60mph and 70mph), so that I know how fast I am driving based on RPM as well as the speedo. That has saved my bacon a couple of times, when the speedo has failed. I could still drive safely and without risking a ticket until I could get to a garage and get it fixed.


Our customers sell eggs. The prices are calculated to thousandths of a cent. Most currency conversions run to 4 or 5 DP. In the finance department of a large chemical company, we had to run the financial reporting to 5DP.


You make my point for me. Somebody noticed that the results being produced by the chip were incorrect and reported it. The fault was corrected. If nobody had known how to manually calculate the math, they would never have noticed that there was a problem, until things started to crash, tollerances in new equipment were too tight and engines seized etc.


Some and some. But that is completely irrelevant. I know, looking at the total of the receipt that something is wrong, whether the cashier has entered something incorrectly or a price is wrong in the machine is totally irrelevant, I am being charged the wrong amount. For the little extra effort I make, I ensure that nobody rips me off.

I had that the other week, with an offer at work, where there was a discrepancy of 5,000€ in the calculation of the offer. If I had just have accepted the total and signed that off, my boss would have crucified me!

It's snap recall they want, that's what my wife (primary school teacher) ratels me. If you say to a child 7x12 they'd have to give the current answer immediately.

My mum tried to get me to do this trick when I was a child. Every bloody day. Again, she was a primary school teacher and felt it was a failing if I could not do that. I never could then, and I still can't do it. I can work things out even though maths was never a strong point.

I can cope with tables 1-5 and 9, the others I simplify to calculate (4*7=2*2*7 etc).

I wouldn't rely just on memory, it can be flaky, especially if stressed or depressed.

The way i do it is : If it's mutliplication I prety much work it out. If it's division, I use something akin to Newton's approximation methods to get a rough answer.

if I need an exact answer I use a calculator.