Okay. And division....?
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2+2+2+2+2+2+2+2+2+2+2+2+2+2-2+2 x 0?
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Posted 7 months ago #
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but this is one of the problems of broken Britain; people would prefer, on the whole, to be ignorant as if it helps them in life somehow.
^^ Wot I said. And I stand by it.
Posted 7 months ago # -
Oh and..
no-one ever writes "a + 4 x b"
Well, in C code that would be:
x = a + 4 * b;
In Excel you would write:
= A1 + 4 * B1
So clearly coders and people that use spreadsheets do it.
And obviously if you had to enter it into a calculator yourself then you would need to use the multiply button at the appropriate point, no?
Posted 7 months ago # -
I use spreadsheets, I would write =A1+(4*B1)
I like to think brackets are a bit like paragraphs. They make things easier to read even though they don't always change the content/result
Posted 7 months ago # -
"Okay. And division....? "
...does not involve the multiplication sign. I had absolutely no idea what point you were trying to make with it, so I ignored it
If I think about it then I guess you mean something like: what about "2 + 2 ÷ 2", but your post is written in the way division is written in normal mathematical circumstances, ie with precedence quite explicitly conveyed. In any case, it's the same thing: I've not seen "÷" used in anger for the best part of 30 years.
"So clearly coders and people that use spreadsheets do it."
1. That's the asterisk, not the multiplication sign. (See also "/" vs "÷" for all these points)
2. Use of the asterisk implies a context, ie computer code.
3. Once you have context, you can be more sure of correct precedence.
4. In that context, there is no alternative syntax, hence the asterisk is required in order to perform multiplication and hence everyone who understands the asterisk as a multiplication operator is likely to be familiar with both the general concept of non-linear precedence and the relatively arbitrary precedence which specifically applies to it - this is very, very different to the case of the multiplication sign, which is almost totally redundant beyond teaching people the basic concept of multiplication.I'm totally familiar with precedence in the context of computing. Had the question been,
Here's some Javascript:
var i = 2+2*0;
alert(i);
What is displayed in the dialog?Then the answer is "2", job done. The context is Javascript and precedence is indisputable - but you need to either know Javascript or make an assumption.
Had the question been,
Here's some pseduocode:
i = 2+2*0;
print(i)
What is displayed?Then the answer would be "2, assuming the operator precedence is conventional and you haven't defined some bonkers language". The context is computer languages and the precedence is standardised, but there's still a small assumption you need to make in order to give a simple answer.
But ask any non-programmer the above questions and you'll get a selection of answers including 2, 0, "could be 0 or 2, I dunno" and "no idea", because they probably don't know how precedence is defined for those domains.
Most people simply don't need to know operator precedence in the real world. There's no shame in it.
Also, people who are familiar with operator precedence conceptually and who know a specific precedence in a specific domain and using specific operators (such as me) simply don't need to know specific precedence using operators that they never use (let alone operators that no-one uses), and - more than that - it would be foolish to assume that the specific operator precedence which they know from their familiar context would be universally applicable in all contexts.
Posted 7 months ago # -
everyone who understands the asterisk as a multiplication operator is likely to be familiar with both the general concept of non-linear precedence and the relatively arbitrary precedence which specifically applies to it
Not arbitrary at all - exactly the same rules as elsewhere.Most people simply don't need to know operator precedence in the real world. There's no shame in it.
There's shame in attempting to argue that those who do know it are wrong. Or in then trying to make out that such ignorance is somehow cool.Posted 7 months ago # -
but your post is written in the way division is written in normal mathematical circumstances, ie with precedence quite explicitly conveyed
Really, look at the equation. Is the term in that numerator equivalent to
(4+a) / bor4 + (a/b)then?If you know the correct answer then you are applying BODMAS. Well done.
See also "/" vs "÷" for all these points
I must have missed the meeting where it was decided that / is only used in computer code.
That equation from the discussion on Vieta's formulas. François Viète dies in 1603. Not sure what computer he used.
Most people simply don't need to know operator precedence in the real world. There's no shame in it.
I disagree. I think not being able to do basic arithmetic that a 9 year old can/should do, even when given a calculator, is pretty shameful. YMMV.
There's shame in attempting to argue that those who do know it are wrong. Or in then trying to make out that such ignorance is somehow cool.
This!
Posted 7 months ago # -
There's shame in attempting to argue that those who do know it are wrong. Or in then trying to make out that such ignorance is somehow cool.
Yes I agree but you're onto a loser, either you are arguing with idiots in public or you're being trolled, either way you lose.This!
Even tho you are correct
Posted 7 months ago # -
In the spirit of genuine enquiry, how many people can recall instances of needing to remember BODMAS in their working lives? All I have is a dim recollection from school that has never been used since. I am quite prepared to accept that this may be unusual.
Posted 7 months ago # -
you are arguing with idiots in public or you're being trolled, either way you lose.
But that describes every day on STW
how many people can recall instances of needing to remember BODMAS in their working lives?
I can. Obviously. But I am likewise prepared to accept that may be unusual.
I wouldn't say I "remember BODMAS" though, as I didn't know that mnemonic till this thread, I just know the right order. It's more or less built-in these days.
Posted 7 months ago # -
Hugely impressive this is still going:
Posted 7 months ago # -
I wouldn't say I "remember BODMAS" though, as I didn't know that mnemonic till this thread, I just know the right order. It's more or less built-in these days.
Yes, I don't remember the mnemonic, either. But I'm nearly as old as you!
Posted 7 months ago # -
Basic maths is important in everyday life, its just that we take it for granted.
The one I love is:
The stock market/price of something goes down by 5%
The next day, the price rises by 5%And the number of people who say, "phew, back to where we started!'.
It makes you want to weep.
Posted 7 months ago # -
Percentage changes are important in my work, which is why I'm careful to get them right. But my question was specifically about BODMAS.
Posted 7 months ago # -
how many people can recall instances of needing to remember BODMAS in their working lives?
Well I certainly used operator precedence this morning when I was calculating the cross sectional areas of some pipework. Granted I didn't specifically think BODMAS but I did make sure that I squared the diameter before doing the multipication or division.
Posted 7 months ago # -
The stock market/price of something goes down by 5%
The next day, the price rises by 5%And the number of people who say, "phew, back to where we started!'.
Yes, it's just like getting used to the fact that if you travel 100 miles north, 100 miles east, 100 miles south and 100 miles west, you don't end up where you started.
Posted 7 months ago # -
how many people can recall instances of needing to remember BODMAS in their working lives?
As explained numerous times up there, shop workers who deal with cash do it daily without even thinking about it.Posted 7 months ago # -
"Not arbitrary at all - exactly the same rules as elsewhere."
That means it's consistent, not that it isn't arbitrary. The world could have defined addition and subtraction as having precedence over multiplication and division.
"There's shame in attempting to argue that those who do know it are wrong. Or in then trying to make out that such ignorance is somehow cool."
I was doing neither - not sure what your point is.
"the term in that numerator"
Whoops - sorry. You got me there. I skimmed it and saw the large division symbol but missed that one.
"That equation from the discussion on Vieta's formulas"
I notice the use of nice clear parentheses in it
"I disagree. I think not being able to do basic arithmetic that a 9 year old can/should do, even when given a calculator, is pretty shameful. YMMV."
No, MMdoesn'tV, but what I'm trying to say is that there's a difference between being able to do something and being able to understand something that is written. Now, I'll grant you, that second part is still important but it's different. The thing is that in this specific question, the way it's written is a way in which no-one writes things outside of early education, so it's easy to forget. I can do maths pretty well, but to be honest, I either forgot or didn't think hard enough, because I've not seen anything written in that form and with that operator in nigh on 30 years.
When I get to the point in life where my son is learning calculus and starts asking me questions about integration and differentiation, I know that despite being fluent in it 20 years ago I'll have to read up on it again before I'll be able to help. The reason for this is that I simply haven't needed to do any calculus for about 15 years.
Now, the thing is that pretty much everyone can add "2 + 2" and can keep going with that. Pretty much everyone can multiply "2 x 0". People could forget what "2 + 2 x 0" is because they haven't had to deal with arithmetic operator precedence in decades.
The thing is that the STW population all sits at computers, so it's a fairly numerate place. Everyone who's posting now is probably at work, which implies they do a numerate job at a computer - as a population sample it's probably above average intelligence and above average in terms of numeracy and literacy, and crucially probably above average in terms of needing to deal with numbers on a regular basis.
But still very few of us would ever see an expression like "2 + 2 + 2 + 2 + 2 * 0" which - don't ignore this point because it's important - is designed to trip people up.
I've forgotten some of my calculus. Some other people have forgotten some of their operator precedence (or in some cases haven't, but have just made a mistake because they haven't concentrated enough on some totally irrelevant question on Facebook - whoop-de-doo). It's the same thing but on a different level.
I'm not saying innumeracy is cool, and if that's what anyone infers that from what I've said then their literacy is as questionable as anyone's numeracy. But there is no shame in forgetting things that you simply don't need to know. (Should I be ashamed that I can no longer speak Latin?) Forgetting or mistaking operator precedence in that equation is not the same thing as being unable to deal with numbers, it's simply not being able to readily recall a piece of syntax which is pretty much unused in anyone's life.
While we're here, assuming you have a full driving licence, without looking it up what's the stopping distance of a normal car at 60mph? You know, one of those pieces of information you were taught once and have never needed since. If you get it wrong, can I start a thread to take the piss out of you and complain about Broken Britain?
Posted 7 months ago # -
if you travel 100 miles north, 100 miles east, 100 miles south and 100 miles west, you don't end up where you started.
Provided you start in the right place you do.Posted 7 months ago # -
As explained numerous times up there, shop workers who deal with cash do it daily without even thinking about it.
Do they? Or do they just count out the change? It's a long time since I worked in a shop...
Posted 7 months ago # -
In the spirit of genuine enquiry, how many people can recall instances of needing to remember BODMAS in their working lives? All I have is a dim recollection from school that has never been used since. I am quite prepared to accept that this may be unusual.
Yesterday, when I was writing a very simple script to check whether a given number in a sequence was even or odd.
Also when I wanted to buy a sandwich and needed to know if I had £2.30 or £34,000 in change in my pocket.
Posted 7 months ago # -
While we're here, assuming you have a full driving licence, without looking it up what's the stopping distance of a normal car at 60mph? You know, one of those pieces of information you were taught once and have never needed since. If you get it wrong, can I start a thread to take the piss out of you and complain about Broken Britain?
There is a difference between learning a fact and learning a rule.
Posted 7 months ago # -
The world could have defined addition and subtraction as having precedence over multiplication and division.
No it couldn't - it's far more fundamental to the whole way maths works.But still very few of us would ever see an expression like "2 + 2 + 2 + 2 + 2 * 0" which - don't ignore this point because it's important - is designed to trip people up.
Yes, but it's quite clearly designed to trip people up. Hence anybody with any sense at all would look at it quite carefully. The issue being people who don't know the correct way to do it when they do think about it carefully (and then attempt to justify their incorrectness).While we're here, assuming you have a full driving licence, without looking it up what's the stopping distance of a normal car at 60mph? You know, one of those pieces of information you were taught once and have never needed since. If you get it wrong, can I start a thread to take the piss out of you and complain about Broken Britain?
Ner, ner, ner - strawman alert, strawman alert.Posted 7 months ago # -
While we're here, assuming you have a full driving licence, without looking it up what's the stopping distance of a normal car at 60mph
240 feet. About as useful in my everyday life as remembering BODMAS. Why is my brain cluttered with such useless facts?
Posted 7 months ago # -
Should I be ashamed that I can no longer speak Latin?
ecce in pictura est puella.
Posted 7 months ago # -
Also when I wanted to buy a sandwich and needed to know if I had £2.30 or £34,000 in change in my pocket.
No you didn't.
Posted 7 months ago # -
That means it's consistent, not that it isn't arbitrary. The world could have defined addition and subtraction as having precedence over multiplication and division.
no.
in your pocket.
2 x £1 coins
0 x £2 coins.how much cash do you have. a) £0 b) £2
there is a reason that we do it like this.
Posted 7 months ago # -
I get your point Bez, but the whole idea that this is some arcane piece of knowledge that no one actually uses still sticks in my craw.
As folk keep saying, people do this all the time with change and just don't realise it.
Going back a bit, you said an equation like:
y = c + mx
Is obvious because it doesn't actually have a multiplication sign in it. Odd, but fair enough.
So what do you do when you need to stick some figures in that?Say I tell you "Right Bez, m = 1.4545 and c = 10, what is y when x is 6.2352"
Okay you might not write down the expanded equation with a multiply sign in it, but you're presumably going to reach for a calculator (unless you're better at multiplying in your head than me) which means you'll be needing to press that multiply button at the correct point and you'll need to know what order to enter it in.
No?
Posted 7 months ago # -
"As folk keep saying, people do this all the time with change and just don't realise it."
No. Absolutely irrelevant, and this is key to the whole discussion.
They do the maths, yes. They don't write down an expression on paper. That's one of my key points - the ability to do something is not the ability to read an expression of the act.
Take Prince as an example. Love or loathe his music, anyone who's seen or heard him live should attest to the fact that he's a musical genius - plays just about every instrument, each of them better than most people play one, and is one of the most prolific writers on the planet into the bargain. But allegedly can't read standard musical notation. This does not make him incapable of "doing music", though it would - by definition - make him illiterate in the context of standard notation. They're quite different.
Picking coins out of your pocket and figuring out what you've got is the act of doing some maths, and is absolutely not the act of expressing the operation you performed in a specific notation, nor is it the act of reading an expression that someone has written to describe in atomic detail the process they performed in figuring out whether they could afford a sandwich.
"Going back a bit, you said an equation like y = c + mx is obvious because it doesn't actually have a multiplication sign in it. Odd, but fair enough."
It's no more or less inherently obvious. It's arguably more obvious to those who "do maths", but by virtue of being more familiar.
"Ner, ner, ner - strawman alert, strawman alert. "
An arguably poor analogy, but not a straw man; since I'm not distorting the opposing argument, I'm merely seeking to test it against an alternative scenario.
Posted 7 months ago # -
Hugely impressive this is still going
Yeah, but what is it about ?
Posted 7 months ago # -
But still very few of us would ever see an expression like "2+2+2+2+2 * 0" which - don't ignore this point because it's important - is designed to trip people up.
FTFY
Posted 7 months ago # -
Has anyone googled it yet? After all, that will guarantee the right answer.
Posted 7 months ago # -
An arguably poor analogy, but not a straw man; since I'm not distorting the opposing argument, I'm merely seeking to test it against an alternative scenario.
You're suggesting your alternative scenario is directly equivalent, hence strawman.Posted 7 months ago # -
"No it couldn't - it's far more fundamental to the whole way maths works."
Well... yes, though I'm disappointed you didn't go to the effort of an example
Posted 7 months ago # -
"You're suggesting your alternative scenario is directly equivalent, hence strawman. "
Touché
Posted 7 months ago #
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