KS2 maths question

[FiveStoryFire]

Multiply the sum of 16 and 9 by 8.

What is the order of operations please?

I agree that's a logical order to proceed but you are making a fatal assumption that once pupils are confident with a skill they will be forever confident with it as they learn new things. They won't!

I used to be a maths teacher. You can get a student confident solving Pythagoras theorem questions, then do a few weeks of trigonometry and suddenly they appear to have forgotten or are confused when you slip in a Pythagoras question. This is what makes maths hard for many to learn, combining your knowledge and recalling what skills are relevant to a problem that is not like the one you have just been taught.

On the topic of word problems causing problems with order, it's more than language can be ambiguous. So if I told you to add up my spending today and said it was 8 lots of £16 plus £9, you might be unsure if I meant 8 x (16 + 9) or 8x16 + 9.

The easy way to look at it is multiply the sum (16+9 ) by 8. So you need to do the sum first, in order to be able to multiply it.

Thanks for that. It's like the first 27 replies to the OP don't exist...

The key is that "and" is an addition word and by either a multiplication or a division word. So Multiply the sum of 16 and 9 by 8.

16 and 9 = 25. Multiply the sum...(25)... by 8 = 200

Lougle - I don't think that's helpful:

"The product of 7 and 5" - and is being there in a phrase denoting multiplication not addition.

"Increase the amount by £5" - by is being used in a situation requiring addition.

Thanks for that. It's like the first 27 replies to the OP don't exist...

Point taken Dad.