Intelligence on the internet

[Wezzel]

Well here's my two'pennerth. I went to the local comprehensive (left in 1978). I clearly remember being taught the order of mathematical operations.

It's not about how good the school was it's about how good your memory is!

 

[ScottM]

Brackets are only shown in school to help people who don't understand the basic order principles (from the 1700s I believe). Like training wheels :)

We must have all been thick at my grammar school then.

Not at all, as I said ages ago (I know it's a lot to go through) I don't really remember it (BODMAS). I remember being taught the orders, but I'm guessing it's only stuck with me because it was a subject I was interested in. I remember seeing brackets used right up past 4th year with a real press on using the order of operations during the higher.

This whole thread has been devisive from the start designed to lure people into showing themselves up.

I have never heard of BODMAS or any order in which you are meant to work out an equation. But as i said we must all have been thick at my school.

Did you read the first page?

The thread ended up at quite a tangent of the point I was trying to make, my focus wasn't at all on the problem. It's just interesteing when they pop up on my page, as there isn't a simple google solution, and the people on my friends list who always seem to know the answer to everything get it wrong more often than not... and call people posting the correct answer stupid and the like.

My original point was that people use and depend on the internet a whole lot more than they should, and some even use it to project a level of intelligence much higher than they really have.

 

[Cononthebarber]

Well this certainly has been an enjoyable thread to read through loving how one little equation has led to so much controversy...which by the way is the entire point of having the rule of BODMAS and why "they" made it up (i.e. the gods of maths or whoever?) because in maths you can't have uncertain answers...you need one...CORRECT...answer :thumb:

So yes the answer is definitely 12, even my 4 year old samsung phone gets it right AND its waterproof! This is not about showing who is stupid or not, as its clearly not stupid to forget and/or not know about some rule of mathematics, but its good to learn though isn't it? Remember, learning's half the battle... :)

 

[BIGJIM72]

Never heard the phrase BODMAS until now,never needed it,probably never will.I think somewhere in there I agreed with you on the OP. With the tech we have available to us now anyone can search for information & come up with an answer,but surely the intelligent part is analysing whether that answer is correct & giving sound reasoning as to why.

 

[Hawks]

I didn't think this post would become so controversial - amusing in places and I hope that a couple of people have just tried to get others to bite.

 

[Jeltz]

I was taught BODMAS at about 11 of 12, I asked my son (12) whether he had heard of it and he said yes he had been taught it recently. It is just the order in which a sum like that is supposed to be done as if you don't then the answer will come out differently.

In a real world situation you would understand where the numbers are coming from and how they should be used so, as its stands, its simply a maths problem and one that requires an understanding of the sequence of operations that should be carried out to arrive at the "answer" that complies with current mathematical convention.

If you carry out the operations in a left to right sequence you will get an answer that does not comply with mathematical convention, simple as that. Is that wrong, well yes because its a maths problem so has to be answered in line with mathematical convention.

 

[TheMumbler]

I'm out. There's clearly no comprehension of the point I was trying to make.

Welcome to the internet!
For what it is worth I agree with your assertion that BODMAS is better described as a convention or rule than a law in that there is no necessary reason that I can see that it must work like that. I am not a Mathematician or a Logician so I may be missing some fine detail here. There is no necessary reason, outside of convention, that I can see that dictates that multiplication absolutely has to come before addition. That said, I struggle to see how you could avoid prioritising brackets without making life difficult.

However life is full of conventions and they are, at times, very useful things.

This whole thread has been devisive from the start designed to lure people into showing themselves up (snip)

I think lure is a bit strong from where I am sitting, although there may be a little trolling going on once the thread gets started (not on my part I hasten to add).

Worth remembering that it is notoriously easy to rub each other up the wrong way on teh interwebs especially when alcohol is brought into the mix as it often is on a brewing forum. Who would have thought that mathematics would need to be added to religion and politics as no-no's for polite conversation :)

 

[ScottM]

Welcome to the internet!
For what it is worth I agree with your assertion that BODMAS is better described as a convention or rule than a law in that there is no necessary reason that I can see that it must work like that. I am not a Mathematician or a Logician so I may be missing some fine detail here. There is no necessary reason, outside of convention, that I can see that dictates that multiplication absolutely has to come before addition. That said, I struggle to see how you could avoid prioritising brackets without making life difficult.

However life is full of conventions and they are, at times, very useful things.

It's a requirement and absolutely must come before addition, as if it doesn't... the wrong answer can be calculated. In fact without using it, numerous wrong answers can be found. There is no law/rule/convention in math that states calculations should be done from left to right. We learn to read from left to right, hence why we automatically do things that way. There is no directional order to solving a mathematical equation, you can start anywhere you like and as long as you follow the rules... you will come to the same answer/conclusion as starting from any other position. This was my example on page 2 or 3 (lot to go through I know).

 

[TheMumbler]

I am not arguing that this isn't the convention to follow or that by not following it you will get a different answer to the one which was intended by the person writing the sum. However, so far as I can see there is no necessary reason why we must follow that convention for mathematics to work.

We could have a convention that says always work left to right. As it happens we don't but that convention is not logically impossible so far as I can see.

For example the symbol for the operation minus is "-" but there is no particular reason beyond convention that we agree to it. If we all agreed tomorrow to use the symbol "#" (pretend that "#" is an entirely novel symbol to avoid issues of needing to replace it) to mean minus the system would still work provided everybody used the new convention. The way the operation works is, I think, logically necessary for maths as we understand it to work though. So no matter how we denote things what we would write currently as 1+1 but in the new system that I am imagining would be 1#1 must equal 2 logically speaking. Incidentally, 1+1=2 has been demonstrated using formal logic by Bertrand Russell I think.

There is a difference between a convention and a law in terms of the philosophy of science, which I believe was the point that jarenault was making.

As I said I am not a mathematician or a logician but I don't think that anything that you have said actually argues against my point.

 

[robsan77]

*sigh* (not aimed at anyone in particular to cause offence, just about the general situation)

I found this thread quite interesting for many reasons but I'm bored now.

 

[ScottM]

I am not arguing that this isn't the convention to follow or that by not following it you will get a different answer to the one which was intended by the person writing the sum. However, so far as I can see there is no necessary reason why we must follow that convention for mathematics to work.

We could have a convention that says always work left to right. As it happens we don't but that convention is not logically impossible so far as I can see.

For example the symbol for the operation minus is "-" but there is no particular reason beyond convention that we agree to it. If we all agreed tomorrow to use the symbol "#" (pretend that "#" is an entirely novel symbol to avoid issues of needing to replace it) to mean minus the system would still work provided everybody used the new convention. The way the operation works is, I think, logically necessary for maths as we understand it to work though. So no matter how we denote things what we would write currently as 1+1 but in the new system that I am imagining would be 1#1 must equal 2 logically speaking. Incidentally, 1+1=2 has been demonstrated using formal logic by Bertrand Russell I think.

There is a difference between a convention and a law in terms of the philosophy of science, which I believe was the point that jarenault was making.

As I said I am not a mathematician or a logician but I don't think that anything that you have said actually argues against my point.

I understand what you are saying, it was when you wrote you can't see any reason that it must work like that that I was referring to.

It must work like that, as if it doesn't you have the potential of getting to the incorrect solution. It's not something that you can choose to ignore if the correct answer is required.

I'm no mathematician either, I just follow the laws that I remember to the best of my ability when trying to solve something (I had a nightmare with trying to work out the FG lol).

 

[Russ146]

If you really want to make your head hurt try this:

A man and a woman are waiting for a bus

The Man's mother is the woman's mother's only daughter

What relationship are the two on the bus stop.

 

[Teenage Kicks]

If you really want to make your head hurt try this:

A man and a woman are waiting for a bus

The Man's mother is the woman's mother's only daughter

What relationship are the two on the bus stop.

mum/son?

 

[Crastney]

the reasoning behind BODMAS - is partly hierarchical and partly logical.

and it doesn't help that the question only uses 3s.

Multiplication can be broken down into addition - 3*2 is (either) = 3+3 or 2+2+2
because multiplication is commutive 3*2 = 2*3
Exponenets/Indices - can be broken down into multiplication - 3^2 = 3*3 = 3+3+3

so 2+3*4^2 = 2+3*(4*4) = 2+3*(4+4+4+4) = 2+(4+4+4+4)+(4+4+4+4)+(4+4+4+4) =50

(1) - 2+3*4^2 = 4^2*3+2 = 3*4^2+2 = 2+4^2*3
If you work out these left to right you get ((2+3)*4)^2 = ((4^2)*3)+2 = ((3*4)^2)+2 = ((2+4)^2)*3

(2) Which gives 400 = 50 = 146 = 108

We know that line (1) is true because 2*3 = 3*2, etc.
but line (2) is clearly wrong, and would lead to all sorts of problems, so we need to use bodmas to provide consistency, so that we always get the same, correct, answer, and so that 1+1=2 and not 14, 38 or 367,594.

 

[Wezzel]

That's completely brilliant and makes perfect sense. I wish you had been my maths teacher in school. If you were I could be a professor by now!

Thanks :-)