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BODMAS

(40 Posts)
Elegran Tue 18-Sept-18 11:08:20

Thinking about it more, writing a sum as 5 + (3 x 4) = ? is the beginning of using algebra - a way of logically setting out the sum for a problem which in words would be "I have five single oranges and three packs of four apples each. How many pieces of fruit do I have?" It gives the right (common sense) answer, which you wouldn't get by leaving out the brackets and working it out from left to right in the order it is written.

Jalima1108 Tue 18-Sept-18 11:03:58

I doesn't make much sense without any brackets anyway - the answer could vary as Joelsnan has demonstrated.

We used the BODMAS method too, but without knowing what it was called.
Some algebraic equations we used to do would cover more than one page, so brackets were essential part.

Blinko Tue 18-Sept-18 11:02:44

I didn't come across BODMAS at the various schools I attended in my travels as an army child. It could have been one of those 'rules' that fell between two schools so I missed it.

I can't say I've missed it.....

Elegran Tue 18-Sept-18 10:59:41

Sounds as though you are of my vintage, Auntieflo. I think we were told the BODMAS thing in primary school, when we first started doing multi-part sums, but it was a long time ago. Maybe it was when we were in secondary and starting on algebra, where the sums get even more complicated and the rules are more essential.

ginny Tue 18-Sept-18 10:58:19

I was at school in the 60’s and have never heard of it.

Auntieflo Tue 18-Sept-18 10:48:08

Apologies to all. I left school in 1957, and I didn't get my GCE '0' level maths. sad so I evidently wasn't concentrating

kittylester Tue 18-Sept-18 10:36:37

I use BODMAS too.

Elegran Tue 18-Sept-18 10:36:12

Starting by sorting out the brackets is obvious, because that is a mini-sum of its own. If you wanted to get the first answer I reached, you would put the (5 + 3) into brackets.

Elegran Tue 18-Sept-18 10:33:05

My dark ages were the 50s. We used BODMAS then too.

Elegran Tue 18-Sept-18 10:32:26

For instance, with the sum 5 + 3 x 4 you could start by adding the 5 +3 (and get 8) then multiply that by for, ending up with 32.

If you follow the BODMAS rule, which I remember from my schooldays so it is not a "newfangled" thing, you would do the parts in the order Brackets, Of, Divide, Multiply, Add Subtract. You would start by multiplying 3 x 4 (and get 12) then add the 5 to that 12 and end up with 17.

I think the order was settled on just because of these possible differences.

oldgoat Tue 18-Sept-18 10:26:03

We used BODMAS at school in the dark ages (1960s ). It's not new.

Auntieflo Tue 18-Sept-18 10:13:32

Is it me, or have these new rules made it more complicated?

Joelsnan Tue 18-Sept-18 10:03:40

Thanks Marydoll
I will check this out.
Why though does it give a markedly different answer to the method of calculation I and obviously many others were taught. Which is the right answer?

Marydoll Tue 18-Sept-18 09:41:29

Joelsnan. BODMAS is taught in maths lessons schools. It is a set of rules, used when doing multiple calculations.

This may explain it. www.mathsisfun.com/operation-order-bodmas.html

Joelsnan Tue 18-Sept-18 09:36:46

I occassionally do those games that appear on Facebook, usually the ones where you have to calculate the answer.
I always use mental arithmetic, the way I was taught at school and am reasonably confident in my answer (after check and re check).
My posts often concur with an average number of other posters however there are some whose response is quite different and alongside their response they usually put 'use BODMAS'.
I have seen this word before, where has it come from? I have no idea what it is and why it gives a different answer. Which one is considered right. Is everyone else now using BODMAS in their calculations?
Confused!