Monthly Archives: April 2017

BIDMAS. BODMAS. Whatever. What is it?

BIDMAS. BODMAS. Whatever you call it, chances are you don’t remember it from school (or, as I maintain, never learned it in the first place).

It can, however, make a huge difference when you’re doing mixed calculations, and nowhere is this more visible currently than on social media.

You’re bound to have seen them: those maths problems using pictures of burgers and fries – or apples and bananas – or bottles and glasses of beer – where you have to work out the value of individual items, then solve the calculation at the bottom of the image.

As I was at first, you are probably gobsmacked by some of the answers people give: how can 5 + 1 x 10 come to 15? Surely that’s wrong, yet quite a few people are insisting that’s the right answer, even though you and many others make it 60.

And what the hell is that word some commenters seem to be shouting: “BIDMAS”?

BIDMAS is a mnemonic for remembering the order of operations in any mixed calculation: Brackets, Indicies, Division, Multiplication, Addition, Subtraction. (Apparently, we all learned it at school; I’m certain I must have been away that day, as were many others.)

Had the problem been written (5 + 1) x 10, then the answer would indeed be 60, but with the absence of brackets, we have to go with the next operation in the order of importance for that problem, and in this case it’s multiplication.

So, the correct order of operation is 1 x 10 (which = 10) then + 5 (which = 15).

So no – you don’t have to be a genius to solve these.

Here’s a link to my free video, in case you’d like to see how it’s done:

A more in-depth look at how BIDMAS/ BODMAS works will be on my full course of KS2 maths for parents, which I hope will be ready very soon.

Watch this space!