To be slightly horrified at how poor my basic skills are?

[primrosesandmaths]

In my professional, graduate profession, I have just been told I have to work out something as a percentage.

I have no idea how to do it.

I shall google - it isn’t an advice thread as such, but my maths is just dire and I can’t help wondering if this is common or whether I am an imposter in my role.

There is too much emphasis in today’s maths GCSE syllabus on things that you never actually need. There should be more emphasis on maths in practice in the real world and understanding basics of finance and economics.

They will either be lovely and try to help and I am beyond help or they will think I am utterly ridiculous. I suspect the latter is true! You just haven't met the right teacher yet. You've already shown yourself capable of putting a lot of effort in, and that's half the battle.

There is too much emphasis in today’s maths GCSE syllabus on things that you never actually need.

Unless you actually want a job in science or engineering, in which case GCSE maths (and increasingly, A Level maths) simply isn't good enough. I know, who'd want a job in science or engineering?

Not me!

QuimReaper (great name)
I'm sure I remember buttonholing my maths teacher about that actually. She was a terrifyingly brilliant woman and I feel sure she rattled off a few scenarios, but I was still unconvinced, and secretly thought they might be the only three examples, and she might keep them stored up for when people asked, as part of the great Median Average Pointlessness Coverup Conspiracy.

Probably the three most relevant examples for most people, rather than the only three examples.

You use median for data that are either:
(a) ordinal, i.e. on a scale where the intervals between consecutive numbers aren't equal: for example a customer satisfaction scale where it's impossible to say that the difference in satisfaction between a score of 2 and a score of 3 is the same as the difference in satisfaction between a score of 3 and a score of 4
or
(b) interval/ratio (continuous scales where the intervals between consecutive numbers are equal, e.g. time, salary, etc.) but not normally distributed, i.e. a graph of the frequency of a particular measurement against the magnitude of the measurement is not bell-shaped.

But I don't think that explanation would have convinced you.

The point is that an average is supposed to be a representative value. In the salary example someone gave earlier the mean of £20,000 isn't actually earned by anyone, or even close to anyone's salary: 90% of people earn only half this amount and 10% of people earn five times this amount. So it isn't in any way representative.

DDs can do percentage. I can’t, but I have an -OMG I can’t do maths - mentality.

If I’m left alone, and no one wants an answer, then I can do it but the slightest pressure paralyses me mentally.

Here's a concrete example of why the median is useful. Suppose there are seven people in a room fresh from the AIBU thread on what people pay for their holidays. They have incomes of £20k, £20k, £40k, £45k, £50k, £70k, and £100k. The median is £45k (three people earn less, three earn more) and the mean is £49285 (add 'em up and divide by seven), and it's not immediately obvious which is "better".

But imagine someone who earns a million quid a year now walks into the room. The median is now £47500 (four people earn more, four people earn less) which is a useful number. The mean is now £192143, which isn't remotely useful.

I'd argue that in most cases, the median is actually the most useful number, and matches our intuitive idea of what "average" means. When the data is normal, the median and the average are close so it doesn't matter which you choose. When the data has some other distribution, like my example above, then the median is more useful. So why not use the median all the time?

I do actually have a reasonable grasp of the purpose of the median. How to actually work it out, I don’t know, but it is useful!

Unless you actually want a job in science or engineering, in which case GCSE maths (and increasingly, A Level maths) simply isn't good enough. I know, who'd want a job in science or engineering?

I agree, except I do think we have missed the step where we teach children and young people WHY we're teaching them things. It's all very well to say that percentages are important but you need the real world application to go with it; certainly up to KS3 level. There isn't enough practical application taught and I think they'd engage better with it if that were the case (and I'm not talking about two men digging half a hole 😁).

I sat in an AGM recently and watched a room full of intelligent people, many of them small business owners, vote to agree a set of accounts which had an error on them so glaringly obvious that I had to second guess myself as to whether I was wrong or had missed something when I spotted it - because surely someone else would have noticed it? Nope. Not one of them was confident enough to read a basic income and expenditure report and realise that a column of figures couldn't possibly have added up to the total at the bottom.

How to actually work it out, I don’t know

Write the numbers down in order, put the numbers in order, take the middle one (if there's an odd number) or half way between the two middle ones (if there's an even number).

OP, I remember my dad teaching me about percentages before I learnt about it at school.

His way was:

For example, you’re looking for 20% of 374.

You take the percentage you’re looking for and divide by 100. Then multiply that with the whole figure.

So in this case, you divide 20 by 100 which gives you 0.2. Then multiply 0.2 with 374 which gives you 74.8.

Voila. 20% of 374 is 74.8

When I actually got to learn it at school, it was taught in such a complicated way with fractions and whatnots that it made my head boggle as I’m a bit crap at maths. But my dad’s way made clear sense to me and I’ve always stuck with it.

Hope that helps!

Do you have an example of the question you need to work out? Perhaps if you could say what it is you need the answer for, we could walk you through the answer so you can relate it to the question you’re being asked

Was also going to say....

I hate maths, it brings me out in a cold sweat! 😩 but I also think that if you don’t use maths on a daily basis you simply forget what to do. Well I do anyway! 😂

I think what people struggle with maths most is that you are either right or wrong. You can't cover over a mistake with an explanation. I hated maths at school. Actually stomach-churning fear before each lesson, because I just couldn't grasp things, and was in a maths set waaaay above my ability, so I was always behind. I was fine with arithmetic, but geometry, trigonometry, algebra, advanced functions on calculators remain a mystery to me.

And then of course I ended up doing accounts so intensively that I knew to divide by 47, multiply by 7, to work out the VAT at 17.5%... and could almost do it in my head. That's the type of maths that's actually useful, not working out angles in a sodding triangle. How many people use the cos sin tan function on their calculator after GCSE? And how many of us just want to know how much we should tip?

The I do sympathise with all those struggling with maths, but it really bugs me when people say 'when do you ever use algebra/ trig etc in real life?'. As if we use all the other stuff taught in other gcse's more.....who refers to the extraction process of iron (geography gcse) on a daily basis? Or Elizabethan foreign and domestic policy? Or quotes Sassoon poems? Or balanced chemical equations? Or uses their French on a daily basis? Everyone uses trig unknowingly when they decide how to position a ladder. Similarly you use algebra often without knowing it. We all benefit from various things we picked up at school, I don't get why the maths syllabus is so denigrated compared to the other subjects.

Sorry for typos

But a median can be quoted with quartiles, or perhaps the top and bottom quintiles (so that 90% of the population lie between the bottom quintile and the top quintile)

I think you mean 60%. Twenty percent are in each quintile, so the top & bottom quintiles account for 40%, leaving 60% in the remaining three.

And then of course I ended up doing accounts so intensively that I knew to divide by 47, multiply by 7, to work out the VAT at 17.5%... and could almost do it in my head. That's the type of maths that's actually useful, not working out angles in a sodding triangle.

Unless you're a joiner working out how to saw a piece of worktop to fit in the corner of a kitchen, or a carpet fitter working out how many carpet/vinyl tiles you need to cover the floor of a room with angled walls, etc... You're saying what's important in your job, not what's important universally.

I don't think you can blame the education system all your life.
School didn't teach me about social media, for instance, as it didn't exist then.
You want to learn something, learn it.
Google is your friend.

@primrosesandmaths It may not just be about the sums. Have a google of imposter syndrome, its a 'thing' and it seems, particularly widespread amongst women.

Write the numbers down in order, put the numbers in order, take the middle one (if there's an odd number) or half way between the two middle ones (if there's an even number). Or more practically - stick the numbers in a column of a spreadsheet, sort them in order and take the value on the middle line (or between the two middle lines if there's an even no). Or use the MEDIAN function.

I knew to divide by 47, multiply by 7, to work out the VAT at 17.5%.. To work out VAT at 17.5% on, say, £452 - 10% is £45.20, 5% is £22.60, 2.5% is £11.30, add them all up to get £79.10.But that's going the other way - you're finding how much of the total price was VAT. At first glance I thought yours was an approximation, but no, it's exact. Neat! 0.175/1.175.

I think you mean 60%. Twenty percent are in each quintile, so the top & bottom quintiles account for 40%, leaving 60% in the remaining three. No, I mean 90%, I got the terminology wrong! What is the term for the 5% divisions?

". Most people wouldn't be able to work out, say, 27.8% of £24,578.40 "

True. I work in accounts, and wouldn't be able to.

Most people wouldn't be able to work out, say, 27.8% of £24,578.40
Would most people recognise that as being a bit more than a quarter, and therefore a bit more than £6000?

I'm sure most people were taught percentages at some time, and it's only a single operation on a calculator. So what is going wrong? Is it that people rely on the short term "this is how I get the answer" and don't understand why they go through those steps? Usually, if you understand exactly what you're doing, as opposed to remembering a sequence of steps, then it's much more difficult to forget.

Just work out 1% and 10% and go from there

Most people wouldn't be able to work out, say, 27.8% of £24,578.40

Not immediately (although give me a pen and paper and I could), but I would expect an educated person to first of all, be able to estimate it (as someone says, a bit more than a quarter of 25k), and secondly, to work it out with a calculator.

I also just want to say a word in praise of trig and pythagorass theorem. I dont think it is useless at all, even if you dont use it in your day to day life. Its a life skill that most people should at least know the basis