To have wanted to alter this maths display

(36 Posts)
kim147 Fri 05-Oct-12 22:25:01

Was in a year 6 class today doing supply. Looked at the displays up and one of them was clearly wrong. It was the BIDMAS display but the teacher had done it as BI*MD*AS. With the meaning of the letters next to it. Schools will teach it as BIDMAS - and it does make a difference.

But how do you point out a mistake to a professional colleague at a school you want to go back to?

Jenny70 Fri 05-Oct-12 22:27:42

I would, perhaps in a "checking I had it right" - knowing that I was right and they were wrong.

LonelyCloud Fri 05-Oct-12 22:29:11

What does BIDMAS stand for?

I don't remember this acronym from my primary school days...

kim147 Fri 05-Oct-12 22:30:01

I could do what a parent did last week. He was Czech and was in the classroom. Told the teacher their attempt at translating "we are learning to" into Czech was not really intelligible in Czech. It made no sense.

kim147 Fri 05-Oct-12 22:30:48

Indices (or Order)

It's the order of operations. Comes up a lot on Chat ;)

BrianButterfield Fri 05-Oct-12 22:31:04

It's the order in which you do multi-stage calculations - Brackets, Indices (powers), Division, Multiplication, Addition, Subtraction.

spottyock Fri 05-Oct-12 22:31:21

With BODMAS I believe divide and multiply can be done in any order so although its not what you're used to it's not actually incorrect.

whatsonyourplate Fri 05-Oct-12 22:32:48

I thought it was B*O*DMAS?

kim147 Fri 05-Oct-12 22:32:52

Except it's not really as you do either division or multiplication first (depending on what comes first in the sum) and then addition or subtraction first (depending what comes first)

So it's even more complicated - but it's taught as BIDMAS or BODMAS

spottyock Fri 05-Oct-12 22:33:03

Sorry, that was an awful post. Division and multiplication.

BoneyBackJefferson Fri 05-Oct-12 22:35:57

In what way is it wrong?

I have also seen it taught as


kim147 Fri 05-Oct-12 22:37:17

4 divided by 2 x 3 = 2 x 3 = 6

Not 4 divided by 6

4 x 3 divided by 2 = 12 divided by 2 = 6

But it could also be 4 x 1 1/2 which also = 6 (the 1 1/2 comes from 3/2)

It is traditionally taught as BIDMAS / BODMAS

vodkaanddietirnbru Fri 05-Oct-12 22:37:39

Division and multiplication are of equal importance rather than having to be done in a particular order. The same is true of addition and subtraction. You do them in the order you find them rather than have to do division first and then multiplication/addition then subtraction. If the multiplication came first when working left to right then you would do the multiplication before carrying on to the next part of the sum. What was on the wall was therefore not incorrect.

BoneyBackJefferson Fri 05-Oct-12 22:37:40


kim147 Fri 05-Oct-12 22:39:41

Interesting - the USA uses PEMDAS, Canada uses BEDMAS and the UK is BODMAS or BIDMAS

kim147 Fri 05-Oct-12 22:40:30

It was not incorrect - but it was not the standard acronym taught in UK schools.

vodkaanddietirnbru Fri 05-Oct-12 22:41:08

I'm sure we did BOMDAS (Scotland, many years ago)

vodkaanddietirnbru Fri 05-Oct-12 22:42:01

does it really matter as long as they get the operations in the right order and get the right answer?

kim147 Fri 05-Oct-12 22:43:46

Does it really matter? Now that's a good question. Secondary schools teach the acronym as BIDMAS or BODMAS. It's nice to sing from the same hymn sheet.

ja9 Fri 05-Oct-12 22:45:26

I was taught

B bless
M my
D dear
A aunt
S sally

.... So M before D...

vodkaanddietirnbru Fri 05-Oct-12 22:45:58

maybe they've changed it too to match up with the primary school - how do you know how they currently teach it? A lot has changed since I was at school too.

TheFallenMadonna Fri 05-Oct-12 22:46:10

I feel a bit for the teacher with the dodgy Czech translation. I teach a fair few students with very, very little English, and I put quite a lot of stuff through Google translate. I realise it's dodgy, but hopefully less dodgy than my grasp of Lithuanian or Tagalog.

kim147 Fri 05-Oct-12 22:46:36

I also teach secondary maths.

BoneyBackJefferson Fri 05-Oct-12 22:46:55

It is nice to sing from the same hymn sheet, but I taught a child who prefered

WofflingOn Fri 05-Oct-12 22:47:38

'depending on what comes first in the sum'

Don't you mean calculation, kim?
If we are being maths nerds... smile

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