Are kids being taught incorrectly?

[cee-dee]

 I saw what was supposed to be a maths question for elmentary schoolkids on the Daily Mail website.

It was 500 plus 450 divided by 5. The answer was supposed to be 590 according to "the rules of maths".

So if, let's say a large bakery baked a batch of 500 loaves and then another batch of 450 loaves, the total of which was supposed to be sent out in an equal amount to 5 different supermarkets, how many would each supermarket get? I say 190.

So are "the rules of maths" a daft way of teaching kids or not?

[jonatjonatjonat]

Unsure if this is a parody post or not.

'taght'

That aside. BODMAS is the rule that has been in place for a number of years and purely explains how to solve an equation based on how it is written. For 500 + 450 / 5 that means you would do the division first so 450 / 5 which gives 90 then the addition, which gives 500 + 90, hence 590.

Your bakery analogy doesn't work because how that would work as an equation would be written differently.

(500 + 450)/5

[cee-dee]

Before anyone says..... I did edit the title but it seems the edit didn't work.

Going back to the "equation", we live and work in the real world, not in some make-believe hocus-pocus world. Kids need teaching how to work out "proper" sums before moving on to what now seems to be the norm of asking trick questions.

[kidmore_kats]

Or you could just admit you got it wrong?

[thesmokingrunner]

A bit of mathematical sleight-of-hand going on there, cee-dee...

Both you and the Daily Mail are correct. Let me explain:

1. The rule of maths is BODMAS - Brackets of Division, Multiplication, Addition, Subtraction - and therefore in the example given by the Daily Mail the correct answer is 590, as the 450 is Divided by 5 before being (correctly) Added to 500.

2. In your example you ignore the use of invisible Brackets: if a baker bakes a batch of 500 loaves and then bakes a second batch of 450 loaves he has (500 + 450) = 950 loaves. He then divides the total number of loves between 5 different supermarkets, sending 950 Divided by 5 (190) loaves to each.

My maths teacher once "proved" that 2 equals 1 using a not dissimilar mathematical sleight-of-hand.

[jonatjonatjonat]

They are taught correctly.

You just don’t write 500 loaves plus 450 loaves between 5 shops the way you think you do.

As stated, that statement would be written as (500+ 450)/5

[cee-dee]

So, where in everyday life would you use the "rules of maths" way of working something out?

Now, when I was at school (yes, I did attend!!!) a (particularly horrible) teacher was going on about some algebra so I asked where, in everyday life would we use such calculations. He went crackers! I can still see him in my mind with his twisted contorted face with his narrow moustache. The rest of the class laughed (it was at him, not my question) but he didn't see the funny side. Fortunately, after a year he moved on. Goodbye Mr Hodges!

[cee-dee]

I see the spelling is correct now. My edit must have been a delayed action one? 😀

[jonatjonatjonat]

You want to increase the price of your product to account for eBay fees as a business. Postage is separate.

10 + 2 x 1.15

so you only have to increase your price by 30p right?

[1902elder]

What has that got to do with Ebay?

[jonatjonatjonat]

Everything if you want to make the right margin

[magpiecorner1]

Equations very similar to this was always the very first question in the 11 plus exams.

Which means we were all taught maths this way in junior schools in the 1960s.

Just to wake us all up, I imagine.  

[cee-dee]

Still, no-one has come up with the answer to the question, "Just where in everyday life would you use such calculations"? I've said, many times on these forums that an old saying was "KISS" = Keep It Simple Stupid. It seems to me that nowadays  the saying is "MIACAP" = Make It As Complicated As Possible.

[thesmi42]

The answer to your question is... "Countdown" !

Everyday life throws up all sorts of challenges and English Grammar is another example where things aren't always that easy to understand. For example,  I've just seen a book titled "The Pleasure of Reading" by Antonia Fraser...

Well, I'm sure it's a lovely town but I've no real desire to go there.

[jonatjonatjonat]

You have already given an example of when you would use 'such calculations'.

If you have 500 loaves, then another 450 and you need to divide it between 5 supermarkets - how many does each supermarket get.

The calculation is (500+450)/9

BODMAS is taught to 10/11 year olds. Has been around since 1923, but formally became part of the National Curriculum in 1988. You spent your maths lessons torturing your teacher - I suppose that is OK as well.

[cee-dee]

That particular maths teacher spent his time verbally abusing us lads, throwing pieces of chalk at us and being thoroughly unpleasant. I'm glad he moved on after a year.

I thought my question was clear enough, that is, where in everyday life would you use the calculation the way it was set out, ie the BODMAS way?

[thesmokingrunner]

You have already been given the answer to your question, cee-dee.

It's just not the answer you want.

[cee-dee]

The answer I want? It's the answer to the simple question NOT setting out my question in the BODMAS way.

[jonatjonatjonat]

What 500 + 450 / 5?

You are trying to calculate your outgoings this month. You have purchased a new car, lucky you. It's £500 upfront, then you also need to pay the remaining £450 in 5 monthly installments, but month 1 is this month.

Have you got to pay £190 in month 1, or £590?

[cee-dee]

Most normal people would look at that and think, "Ah, so it's £950 eh? Right, I've gotta pay £500 up front, sooooo, that leaves £450 to pay over 5 months. Therefore for each month it's £450 divided by 5 which is £90 a month?

OR, the way you said it, it could be construed as £500 up front AND a payment too..... leaving the rest over 5 months???????? 

For kids, that'd be even more confusing.