I have a slide rule on my desk somewhere.

Mine is in on the shelf next to my desk. It was my father's. I also have his school microscope and a brass protractor.

Mine is one of my grandma‘s - there’s a Helix school one somewhere too. My grandma taught me how to use them as I was interested in how things like that could work when I was a child.

when i was in school we had to learn the times table to 12x by rote
this was mainly because the monetary system at that time was old money
12 pennies to the shilling 20 shillings (240 pennies) to the pound etc

all calculations were done the long way, long diversion and long multiplication
no calculators they had not been invented, everything had to written down the long way or by using log books to 4 decimal points

i can still do it now forwards and backwards and work most everyday calculations out in my head

progress is not always forward thinking ...

same

Also when I lived overseas had to do the whole Rods, Poles and Perches (old units of measurements). Always thought - "whats the use of this" until I work in a land securities dept for my old company and was one of the few people who could take old deeds and work out that they were talking about and convert it to modern units

Which is, with all due respect, like claiming that because you once had to shoe a horse, everyone should have some training as a blacksmith.

The history of civilisation is the history of invention. The history of invention is largely the history of people thinking 'a machine could do this much better than a person'. In pretty much every single case, that has turned out to be true.

In your case, yes, you knew what the measurements meant. If I was in your position I wouldn't know how to convert them. But I know what a search engine is and I bet that could tell me. This is how new skills replace old skills and there's no point teaching children old skills.

As I've said, I have no objection to people being taught how to do the kind of mental arithmetic we all do every day in our normal lives. But the vast vast majority of the population do not need to be able to do 'manual' long division; they simply don't, and a couple of examples where it is necessary doesn't change that. 'The plural of anecdote is not evidence'.

The time spent teaching 95% of the population long division is vital educational time utterly wasted.

Back in the 70s when I did Additional Maths at 'O' Level, the use of calculators had just been allowed.

On the day of the exam itself my calculator started playing up and producing wrong answers. Unfortunately I was a good way into the paper before it produced an answer that was noticeably incorrect and I realised that it gone wrong and I could no longer rely on it. I completed the rest of the exam using my slide rule and log tables and doing long multiplication and division the old way, and then spent the last few minutes going back and checking my answers to the questions I'd done before spotting that the calculator had failed to try and correct any errors it had given me.

Technology breaks down in al sorts of weird ways and until it produces a result that is obviously wrong, people will accept that it is always correct.

That's because pretty much any piece of technology will generally have a better rate of accuracy than pretty much any human.

Obviously, early versions of any technology has issues and possibly should not be relied upon solely. But these days calculators are known to be accurate to the requirements of even quite extreme circumstances.

When I was at school, we had switched to decimal, but we still had to learn up to 12x table and although we all had calculators, and could use them in non-math lessons (physics, chemistry, accounts etc.), we had to do maths long hand. Also no calculators in exams.

But guess what, we have cars nowadays and steel foundaries, but we still have blacksmiths and they still make horse shoes, we didn't just kill all of the horses in the world, because we had invented cars. The blacksmiths still make gates etc. as well.

And if nobody understood math any more, because we had computers, we wouldn't be able to build anything new. Having a machine which can do more complex calculations is only possible because somebody somewhere has the knowledge to tell the machine how to do that! We have seen time and again that moving forwards doesn't mean we should forget the past. Look at all of the math and philospohy skills that were lost with the fall of the Greek and Roman empires, we fell into the dark ages and had to relearn centuries of knowledge.

If we say math is no longer relevant, in a few years we will be reliant on machines that we hope are providing the right answers, because nobody can double check the results. A human can't hope to calculate as fast as a computer and a human can't hope to double check all of the results, but somebody, somewhere still needs to be able to do random checks on those results to ensure that they are accurate.

Machines should be seen as an aid us in improving ourselves. It is a bit like having an accident and not being able to walk. You can either give in and let a machine wheel you around for the rest of your life (stay in a wheelchair) or you can use technology to aid you get back on your feet (crutches, artificial limbs etc.), in the former case you rely on technology to do something for you, in the latter you use technology to help you do something.



If we don't, soon there will be nobody who can teach any
body those skills. How often do you hear stories of the last surviving person who can speak an obscure language is dying or has died and the language is now dead, because there is no longer anyone who can understand it? In the 90s and early noughties this came up a lot.


I think we will have to agree to disagree, I think that long division and multiplication is very important.

Over here there were a lot of painters looking for apprentices and they were having real difficulties, because none of the candidates could do long multiplication and long division. You have a room with walls 5M and 3M long and 2,5M high, you need 3 coats of paint, the paint comes in 5L tins and a litre of paint covers 2,25M²m how many tins of paint do you need?

Such simple calculations are what the apprentice needed to do on the spot. Most of them hadn't a clue how to do that. That isn't rocket science of physics, that is a lowly manual labour job, but they still need math on a daily basis.

My wife works in a kitchen and has to cook reipes for different sized groups every day. That means that she has to take the base recipes and multiply them up to make the right amount of food. She is not good at math, but in the kitchen she doesn't have access to a calculator, so she has to work that out in her head.

I have seen modern calculators also provide screwy results. The problem is, if you haven't learnt how to do the calculations yourself, how do you even spot that the results you are being given are screwy? And if the results are screwy, how are you going to finish your work and provide correct results?

To go back to my first example, if you buy a 4.50€ menu and a 5.50€ menu and the POS says you owe 15€m, would you just pay? Or would you spot that the total is completely incorrect and refuse to be ripped off?

This was in the early 90's so I don't think it would have been easy to just "google" it
I know we didn't have any internet access at work and I don't think even thing the manager had e-mail access (it was before I had by 1st PC - I was using an Atari ST at the time)
However I wasn't saying kids needed to be taught old measurements - but they do need to understand the fundamentals of maths and that includes Multiplication and division

I was not taught slide rules as they were superseded by the time I got to school. However my maths exam were always graded on the theory being right and the numerical answer had next to no value and would not be graded if the explanation was not correct.
Understanding the calculation and knowing what ballpark the final answer should be in is more important than being able to compute it from head.

The calculator I had been used had functioned completely accurately all year. It was only mid-way through the exam that it started producing wrong answers and it took an answer that was reasonably obviously incorrect for me to spot it. And I only spotted it because of my mental arithmetic including times tables.