Maths teachers: 60% x 300 = ?

[wellthereyougo]

DS is in Year 6 and says this question came up in class today. Now I know that ....

0.6 x 300 = 180
0.6 of 300 = 180
60% of 300 = 180

... but I've never seen it expressed as 60% x 300 before. His teacher says the answer is still 180 (as opposed to 18000% which is what most of them intuitively put in their answer, and probably what I would have put). She also said that this is a new question format they will need to get used to with the new curriculum.

Can any other maths teachers confirm this?

I'm not a maths teacher but in my day (80s) we were told that 'x' (multiplied by) can be read as 'of' - so when I saw this, I straight away read it as '60% of 300'.

I teach Year 6 and DearTeddyRobinson is correct. Any time your DS sees X% x .... just read 'of' for 'x'. The curriculum is incredibly intensive now. I never learnt this before I had to teach it!!

It basically means 60% of 300. Just another way of confusing the kids.

My daughter was the first year to sit the new SAT’s and there were two questions worded that way and hey had never been taught it. Good the school is teaching them.

Yep. There was a question like this in the 2016 arithmetic sats paper. Mine had never seen it expressed like this and it tripped some of them up.

Loads of ours got caught out by it expressed as 60% x 300. Also 1/4 x 150 etc.

Well yes, I was taught that too, which is why I know 0.6 of 300 = 180.

However, I've never seen it expressed this way before, and it begs the question of what you would write if you really did want to multiply 60% of something by 300. But perhaps that would have to be written as 300(60% of something).

It isn't 60% of something x 300, it's just 60% of 300.

Sorry, posted by accident.

You would write 60% x something x 300. You could do 60% of 300 first then multiply that by the something because multiplication can be done in any order.

Also, 18000% is 18000/100 which is 180, so that answer is also right in a way, it's just that using the % symbol doesn't make sense in this context. So you replace the % symbol with /100 and do the division.

% is not a unit, so 60% x 300 = 18000% would not make sense in the way that 60cm × 300 = 18000cm would make sense.

Teacher needs to go back and make sure they are confident with % as number of parts per hundred and converting % to fraction I think.

The x should really be of IMO. But I'm a bit pedantic about maths.

What dearteddy said. But also 18000% is 180, so is correct anyway, it’s just different units (expressed as a percentage not an integer)! I.e 18000 percent = 18000/100= 180 (Per means divide and cent means hundred). Ok, usually things are expressed as percentages between 0 and 1, but unless the question specified the answer should be written as an integer, it’s still correct.

60 per cent or 60% means 60 over 100
So the sum written fully would be :-

60
---- X 300. = 180
100

Just read ‘x’ as ‘of’.

3 x 4 means 3 ‘lots of’ 4.

60% x 300 means 60 hundredths of 300.

In other words... for every 100, count 60. There are 3 hundreds, so you need three lots of 60.

Since multiplication is Commutative, it may make more sense if you change order to 300 x 60%.

60% = 0.6 or 6/10 so, 300 x 60% is same as 300 x 0.6 or 300 x 6/10

I was a maths teacher long ago ...

Yes, as others have said, 'per' means 'divide' (like, for instance, if you want speed in miles per hour, you'll need to divide the number of miles gone by the number of hours taken); and 'of' is 'multiply' (or 'times' if you like that better). [Also remember 'cent' is a hundred (think 'century' or 'centipede' etc.)]

So, '60%x300', same as '60 (divide by 100) times 300'. Or, alternatively, '60%x300', same as '60% of 300'. Answer, either way, 180. (Or, of course, as someone else pointed out, 18000%, which is the same thing, '18000 (divide by 100)', that is, '180' again.)

Summary (useful arithmetic fact): ' PER ' means ' DIVIDE '.

I was a maths teacher long ago ...

Yes, as others have said, 'per' means 'divide' (like, for instance, if you want speed in miles per hour, you'll need to divide the number of miles gone by the number of hours taken); and 'of' is 'multiply' (or 'times' if you like that better). [Also remember 'cent' is a hundred (think 'century' or 'centipede' etc.)]

So, '60%x300', same as '60 (divide by 100) times 300'. Or, alternatively, '60%x300', same as '60% of 300'. Answer, either way, 180. (Or, of course, as someone else pointed out, 18000%, which is the same thing, '18000 (divide by 100)', that is, '180' again.)

Summary (useful arithmetic fact): ' PER ' means ' DIVIDE '.

This video explains concept of percent, as 9toe did.
Once dc is secure with the concept, conversion comes automatically.

www.mathantics.com/section/lesson-video/what-are-percentages

Wouldn’t you just times it by 0.6

@Tomorrow.

I think it's the way the question has been written, 60% x 300, instead of 60% of 300. But yeah, once dc can instantly convert % into fraction or decimal, it will become very clear.

I'm old and not a teacher, but I read it as 'of' and assumed that if you were putting it into a calculator you'd think in your head "60% of 300" and you'd type in '300 x 60 %" You'd see the total of 300x60 first (18000) and then when you press % it would show 180.

60% is just a fraction, another way of writing 60/100 or 0.6. Of course you can multiply a fraction by something. His answer isn't wrong but it isn't as simplified as it should be. Like if someone asks you 60x90 and you write 6x900 as your answer - it's true but you haven't really finished.

Your dc just need to understand that 60% is the same as 0.6. So 60%x300=0.6x300=180