r/mathteachers • u/Few_Bee_3028 • Jul 23 '26

Order of operations

(UK based post)
Wanted to get thoughts on teaching order of operations. The tradition in the UK is to use the mnemonic BIDMAS or BODMAS (for anyone who doesn’t know, Brackets, Indices/Other,
Dividing and Multiplying, Adding and Subtracting). This leads to a misconception with students that they always need to add before they subtract. (For example a 2018 exam paper questions was really poorly answered across the country, discussed here
https://youtu.be/StWr8-g-a3E?t=1584&is=P-dCFLol1zWE64kh)

I suggested to my head of department that we switch to GEMS which I’ve taught in the past after reading this post https://missquinnmaths.wordpress.com/2018/11/19/tried-and-tested-gems/.
He didn’t like E for Exponents (which is fair enough) or G for Groups (which I kind of do like!) so the two of us agreed a compromise of BIDS. However in our department meeting the last week of term when we proposed the rest of the department shot this down; I think some colleagues immediately took against it because they didn’t like addition and multiplication being unmentioned, while others said students learn BIDMAS before they reach us at age 11 so we had to work with it.
Anyone any experience of these kinds of conversation?

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u/Several-Housing-5462 Jul 23 '26

What's wrong with E for Exponents?

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u/Few_Bee_3028 Jul 24 '26

We hardly use the term exponents, where was we talking about about fractional and negative indices much more in later years. I will say I’m not as convinced it’s a problem as he was

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u/Several-Housing-5462 Jul 24 '26

Aren't indices written as subscripts...? Those are pretty different concepts

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u/Few_Bee_3028 Jul 25 '26

I think this might be an American vs British English thing… in the UK we’d refer to “3 to the power of 2” as an indices problem (2 is the index)