To ask if you do long multiplication/division regularly?

[BoyTree]

Please settle a debate for me!

Older son is doing long multiplication and it came up that it would have been more important to know the formal 'method' to complete the sum by hand/brain when calculators weren't so ubiquitous. He asked who would still be doing it by hand now and I was stumped!

I can't think of anyone who would routinely do long multiplication using the column method as part of their job, but felt sure I was probably overlooking some vital role. Does anyone here use it or know of a job where this skill would be vital?

There are some people here who, I'm pretty convinced, have forgotten what long division/multiplication actually are. The question isn't "do you ever do mental arithmetic involving division/multiplication" - long division/multiplication is the pen-and-paper method for when it's too complex to do in your head.

I haven't done any since smartphones became a thing. If you have a calculator to hand, and everybody does these days, it's always faster to use it for anything you can't do mentally.

Never.

I had to use log tables and a slide rule to get my Maths O level but I haven't used either of them since 1971.

Haven't done it since I left school 14 years ago.

I do use maths at work but I always use a calculator.

@ThePants999

There are some people here who, I'm pretty convinced, have forgotten what long division/multiplication actually are. The question isn't "do you ever do mental arithmetic involving division/multiplication" - long division/multiplication is the pen-and-paper method for when it's too complex to do in your head.

I haven't done any since smartphones became a thing. If you have a calculator to hand, and everybody does these days, it's always faster to use it for anything you can't do mentally.

well yes.

But some of us said we'd use it both on paper and in our heads.
If I was doing long multiplication in my head though, I wouldn't use the same method as the written method.
And I don;t always have my phone.

@PickAChew

Not on paper but I'm fairly good at chunking up or down in my head and if my head says no, my phone can do it.

I hated maths at school and wasn't very good at it (thanks to a very good teacher I got my O level). Later on I devised chunking for myself for mental arithmetic and was very surprised to find much later that it was actually being taught as a method in school.

Thanks I really enjoy doing it actually, makes me feel like less of a dullard! Last used to calculate tiles needed.

That said, I’ve just been through long division and long multiplication hell with my son so

My general arithmetic is quite good but life is way too short to do long division and multiplication by hand!! Especially when l have got a calculator on my phone. Think your son is right OP!

It’s just a pencil and paper method of dealing with division involving larger numbers so the working is laid out in an organised way and easy to write and see (and check).
It’s exactly the same principle as “short” division. It’s not hard to teach and to explain, and it’s extremely useful (as is “short” division) in developing understanding of decimal fractions.

It's so important that it is not on GCSE maths papers. Adding fractions and circle theorem is on those papers but complex long division isn't.

Not that maths should be about GCSEs though

I was always good at maths, and use quite a lot of maths in my job. I remember being really excited as a little kid by pi, then later calculus, complex numbers etc.

But long division ... it's doable but so bloody tedious. Calculators were somewhat newfangled when I did my maths A levels in 1979 - the numbers were generally chosen (pi as 22/7 etc) so that they cancelled out and you could concentrate on maths not arithmetic.

@chomalungma

It's so important that it is not on GCSE maths papers. Adding fractions and circle theorem is on those papers but complex long division isn't.

Not that maths should be about GCSEs though

but it is taught in year 6? and appears on 11+ papers?

Mindutopia Snap! Have A level English ,and GCEs .However could never get the hang of Maths .Have a really good friend "Charlie"who helps me .Is very kind and patient (Hes a Calculator!) wouldnt be without him .Definitely no test of intelligence, as Judith from the Eggheads has admitted Maths is not her Forte either !

I do and my job isn't maths-y at all. I'm a youth worker and teacher (not Maths). I use them just for everyday stuff like how many coaches do I need to book for an event with x people, how many sheets of paper can each pupil have etc. I sometimes use a calculator but not always, often it's quicker to do it on paper.

I try to insist to dc that they need to have at least some vague idea of what the answer should be because if you type the wrong thing into the calculator you could end up massively wrong. E.g. if you're dividing 1376 by 53, you should know to expect a low 2 digit answer. Imo, you really only get a feeling for estimation like that by practising by hand, because it doesn't go into the longterm memory as easily if everything is automatic.

A lot of things taught in year 6 appear in GCSEs except long division.

I dont. But if I needed to, I could. That's the point of it really.

Nope. And I can't think of a situation where I would need to multiple/divide urgently AND didn't have access to a calculator. I'm with your son.

I'm a primary school teacher. In my non school life I do sometimes use long multiplication but I never use long division, I just use expanded bus stop (ie short division but you will sometimes be carrying two digits over rather than one). I don't think LD is very useful. In fact most of the time I divide by estimating and multiplying instead as I often find it quicker.

Me! I did it through 2 degrees; whilst lecturing, leading a maths/English dept and still do.

Pencil, paper and off you go! I also 'chunk' if that serves purpose.

Why?

1. It's a skill I like to keep up. Gives my brain a regular task
2. Fumble fingers on phones, calculators can cause errors. At least if I DIY it I have an guesstimate to check the answer by. Relying on electronics has caused some dismal errors.
3. What happens if you absolutely must work something out and don't have a caculator or phone to hand? Or am I talking to the perma-phoned?

70044 / 78

With an explanation of how you worked out each step With pencil and paper, long division as taught way back in the 70s! Took about 3 minutes, including finding and pencil and paper! I started by scribbling 78 times table down the side of the paper....gives me a ready reckoner for the long division sum. A tip I was taught before calculators where real!

Chunking would give me a guesstimate of less than 1000 [70000/70] and a bit less than 920 [1000 - (10 x 8)]

I might even do the sums for the chunking on paper... but like the task of long division, so maybe not.

I do it a lot for organising my Cub pack, and personal finances. I also do use it for work reasons, evaluating data etc. I find if it's only a few numbers it is usually easier to just do it by hand rather than finding a device with calculator on it.

Then again, I kinda like numbers.

But as a civil servant I use them a fair amount, even when not in budgeting areas.

As a Cub Leader, organising 24 Cubs (and 3 Leaders) I use both long multiplication and division reasonably frequently to work out costs per person and overall costs.

Yes almost daily in my head. It’s quicker than using a calculator.

I'm a scientist and I do almost everyday, usually when I've forgotten to take my phone into the lab which is quite often.

I was in the bottom maths group and was never taught this stuff. It was only when re-sitting my maths GCSE at a college at the age of 30 that, on the tutor's recommendation, I got a book called Adult Learners Guide to Numeracy. The book actually explains these things, step by step, in plain English. (God knows why schools expect the least able pupils to figure this out on their own with no help at all... at least there's now the internet to rescue those whose teachers can't be arsed.) So with the help of this excellent book I was able to cram enough of this crap into my short term memory to scrape through the exam and get a C. I daresay if you'd asked me a fortnight later to demonstrate long multiplication/division, I wouldn't have been able to. As a kid it was frustrating to never understand maths beyond simple addition or to be able to remember a single times table, but now I'm glad that my mind isn't cluttered up by this mostly useless information. I don't see the point of making yourself work things out with a pencil and paper if you don't have to. It's up there with stinky PE kits and dreary methodist hymns - stuff that no sane adult would invite into their life. IMO.

Never, I have this device called a calculator.

I've never needed to work out the diagonal of a farmer's field having inexplicably measured the other 2 sides either.

I've never needed to work out the diagonal of a farmer's field having inexplicably measured the other 2 sides either.

I have to do the equivalent of that a lot, but on a much smaller scale and 3 dimensions. Except of course I write code to do it because doing it once would be a pain but doing it tens of thousands of times would take days or weeks.

It's the method, the maths not the arithmetic, which matters.