Be Excellent To Each Other

What is 2 + 2 x 2 = ?

I saw a friend (a primary school teacher of 10-11 year olds working in a relatively good Primary School) answer this question earlier and I was surprised at what she answered. What is the answer?

6?

6... order of operations innit, BODMAS and all that

8!

6.

Yes, 6.

That's miles out.
Am I allowed to do another factorial joke?

How you get 40,320 from that I'll never know

Yes, it is 6! She answered 8 and I feel quite disappointed. I wonder what proportion of primary school teachers would get it wrong?

I'm disappointed in MaliA.

MrsA, you are still signed in to the 'Kalmar' sock puppet account.

WTF?

Is that supposed to be a division operator between the first two twos? I thought it was a minus at first, but now I think it's division, in which case 2 x 2 = 4 and 2/4 = a half, innit.

OH feck, I mean 2/2 = 1 and 1 x 2 = 2

Could someone explain to me why some say it's "BODMAS", when clearly "BIDMAS" makes more sense, because I = Indices. What the hell is O supposed to be for?

Oh, and this doesn't surprise me at all. I once sat with a person who was revising for their P-whatever-it-is that qualifies people to be primary school teachers. Some of the things they didn't know made me want to cry. They passed, naturally.

In my whole time at school, I encountered one good maths teacher. She was brilliant. Naturally, she soon left to do something that people actually respect. The rest were either passable or, in several cases, staggeringly inept. One used to give us fake coursework, then laugh at the people who'd done it. After a few years of shit like this, I went from loving and being pretty bloody good at maths to loathing and resenting it with a sulphurous passion.

My maths teacher, Mr "Teddy Bear" Davis, used to say, 'The speed of the class is the speed of the fastest boy,' which meant most of us spent two years trailing behind Pete Dixon and never caught up after that.

No, it reads (left to right) two plus two times two equals

Fair enough.

I need new glasses.

And in that case, 6.

He's got that backwards. You're supposed to spend 3 years waiting for four fuckwits to work out long multiplication (on days when people from another class aren't coming in to beat up the teacher who's only doing your class because he can't control the other one, and all this is something you would stop but really, he actually deserves it), then do your GCSEs a week later, having long since ceased to give a fuck.

Did you know that 0.999999999 recurring is equal to 1?

Why is it six?

That's stupid.

Because you always do multiplication before addition in the usually accepted method of notation. Tis to keep the number of brackets down. So it's effectively (2x2)+2 which is 6. If you want to do (2+2) x 2 you have to use the brackets.

I think the topic heading should be changed... I completely forgot about BIDMAS/BODMAS.

Interesting.

For a while I couldn't even work out how you could possibly conclude that it would be 8 because the proper method is so utterly ingrained in my heed.

If it helps, I've never heard of this BODMAS thing either.

The O of bodmas is ORDERS, ie powers and squares.

Me neither. When did they invent that? It was all SOHCAHTOA back in my day.

I don't recall any particular mnemonics, either, but the correct order seems part of basic understanding. I'm surprised that said friend insists she has no idea what I am talking about, despite being a teacher :/

I just asked my 3 boys what they thought the answer was.

The 7 year old and 10 year old thougt the answer was 8, but the 12 year old knew the answer was 6, he told me that it was because of bodmas, he said he learnt that in year 6, the other two are in year 5 and 3.

Malc

It's 8 to me.

No brackets, calculated left to right.

I just see 2.2 which is "auto brackets". Then plus 2.

But that's horribly wrong because you don't just automatically go left to right. Multiplication and division take precedence over addition and subtraction.

But since when? I've never heard of that before, and I've done maths to degree level.

(I'm not arguing with you anybody by the way, I just can't believe I have got to this point in my life without ever being taught it.)

Since always, I guess! I was definitely taught order of operations at what used to be called "Standard Grade" level maths in Scotland (which is/was the equivalent to GCSE in England).

edit http://en.wikipedia.org/wiki/Order_of_operations

Yup, BODMAS was taught to me in primary school. Multiplication and division first.

Wow, I can only conclude that I have had a really shite education then.

I love getting Bodmas presents - one year someone got me a nice little multiplication table.

without brackets its either, and a nonesense.

the answer could be 6, or could be 8.

Without brackets the order of operations dictates that you do the multiplication first, so the answer can only be 6. That's why we have an order of operations!

Honestly, if you have degree level maths then I can only think that you have probably just forgotten it at some point in time. It's one of the very first thing that children learn when solving their very first simple equations.

I'm sure it is new to me.

My calculator says its 8 and my calculator never lies!

Also, why is it when you rearrange equations then you always do the additions and subtractions first? This order of operations is inconsistent and is farcical at best.

Better (ok, more expensive) calculators will actually rearrange the equation according to the proper order.

The term "Polish notation" springs unbidden to mind

More expensive calculators... like Google, in fact:

Me and my calculator are no longer friends.

Go multiply yourself.

One plus side of this is multiple divisions of the forum.

How should I read that back?

I don't remember being taught BODMAS when I was doing sums back in the 60s. Maybe I was off that day. Or Teddy Bear didn't explain it to me. I know I was ready to kill either him or myself when we started doing quadratic equations; I think that was the point that my life started going downhill.

However, when I was doing my BTEC in Computing, which must have been around 1995, George the maths tutor introduced the class to BODMAS and that's the first time I remember anything about it. And I promptly forgot about it once I had my tercificate in my sweaty paw.

I also remember thinking that I'd never have the need to use quadratic equations in my working life, and so it proved to be. I also thought that no-one else would either, but I was proved wrong when I went to a school reunion a few years ago, when we were discussing that very teacher and class, and one of my ex-classmates, who I think works in engineering of some kind, said he used them on a regular basis.

_{I think he was a lying bastard, but there you are.}

I remember BODMAS vaguely, if i remember correctly it is

B = Brackets
O = Order
D = Division
M = Multiplication
A = Addition
S = Subtraction

You start at the top of the list and work each maths problem from left to right then move onto the next in the list. Hah! i knew my schooling was in there somewhere

I use quadratic equations all the time. Oh, sorry, I thought you said xbox.

I just dropped my packet of crisps, laughing at that (pickled onion Space Raiders, for reference).