BODMAS.. Mistake or correct?

[JellyTots2009]

My friend is at college and today learnt BODMAS. I asked her to send me an equation she had been given and her answer. I worked it out for myself and I got a different answer. Her teacher gave her a different answer too!

So this equation

3x2-4+5/2

Answers were;
-0.5
3.5 or
4.5

Which is correct and can people give their workings out please. I do think I've done it wrong but I followed the order!

@MarshaBradyo

Past ah I see I did a lot of maths at university (economics) so was fine at it at school but for the life of me can’t recall BODMAS. Have been doing it with Ds though

I did a Maths degree at the end of the eighties and don't recall it. Then I went into teaching and by the late nineties, BIDMAS or BODMAS seemed to have caught on.

I can't even remember what the O stands for: pOwers? I for Indices works for me.

In the US, it seems they use PEMDAS (because they talk about parentheses rather than brackets, and E is for exponents). Note that they've switched the M and D.

I got to 4.5 in my head too but as I have a manual (non-scientific) calculator next to me as well as my iphone calculator, I thought I'd try it on both, typing the equation exactly as it is on screen.

Unsurprisingly the simple desk calculator doesn't work it out correctly (it comes out at 3.5.

Perhaps surprisingly the iPhone gets it right even in standard AND scientific mode (rotating the phone).

4.5

@DadDadDad I definitely did BODMAS at primary age in the late 70s.

Somewhere on one of these countless threads (though it might have been a Michaela one) I came across another 'acronym' or a ditty that made it CLEAR that D&M and A&S are at the same level of priority. But I can't remember it.

I view the O as Order or Of.

This is helpful