Working out energy bills and direct debits

Nick_C

Shrimply wrote: »

I don't think you need to worry in the slightest as long as you keep them engaged and interested.

My understanding is that the aim is to get the kids thinking for themselves, and actually understanding what is going on. Yes you can give them simple rules to follow and they might get the answer quicker but that doesn't mean they are following why they are doing it.

e.g.

Giving them the BODMAS rules and written mathematical problems to solve is different from practical skills where you need to work out what order to do the operations based on the question you are trying to answer.

Order of precedence is a convention that removes ambiguity. You don't need to work out what order to do the operations in. There is no logical basis for doing so. You simply follow the rules.

Shrimply

Nick_C wrote: »

Order of precedence is a convention that removes ambiguity. You don't need to work out what order to do the operations in. There is no logical basis for doing so. You simply follow the rules.

Only if you are given a mathematical problem written in that format to solve. Not if you have to solve real life issues dealing with numbers. Knowing the rules doesn't help you write the problem down following the convention correctly either unless you are thinking about why you are doing it and what it means.

This is the difference that people don't seem to grasp. We can easily give children work sheets with lists of problems to work through following the rules that we detail. But that doesn't do anything to teach critical thinking.

Nick_C

Shrimply wrote: »

Only if you are given a mathematical problem written in that format to solve. Not if you have to solve real life issues dealing with numbers. Knowing the rules doesn't help you write the problem down following the convention correctly either unless you are thinking about why you are doing it and what it means.

This is the difference that people don't seem to grasp. We can easily give children work sheets with lists of problems to work through following the rules that we detail. But that doesn't do anything to teach critical thinking.

To create a spreadsheet that calculates the cost of electricity, and to do it in an elegant manner, you need to understand order of precedence. An inelegant solution for people who don't understand the concept would be to use additional cells for intermediate results.

This is a real life issue.

Shrimply

Which is my point really, knowing how to actually do the calculation correctly is far more important than an "elegant" spreadsheet.

And it depends on your definition of elegance in any case, I think I could easily argue that a spreadsheet where each intermediate value was present but hidden was equally elegant while containing a lot more information that could be useful.

Learning the rules when you understand the concept is far easier than learning the concept by being given the rules.

Ilona

You've completely lost me now. No idea what those words mean. I will consult a dictionary.

Ilona

badmemory

Hengus wrote: »

As usual, we have got massively off the topic. The whole point of initiatives such as The Numeracy Challenge is to give people the skills necessary to cope with life and work. Rather than doing maths for maths sake, I can well understand the logic of putting the challenge into Real World situations. It is irrelevant whether the CV is 39.2 or 39.8, or whether A uses a spreadsheet or B uses a calculator, the original post is about simple multiplication, addition and division. We should all applaud and support initiatives like this as it is extremely worrying that in a country such as ours that we still have people who cannot add up or read.

Exactly. There are far too many people that seem to think that is rather clever not to be able to work out what their bill (for anything) should be. Maybe they think it means they appear well off. It doesn't. The rich did not get rich by just coughing up.

One of the things I find worrying is following several mid-teens (regular bad timing on my part) through the check out in Home Bargains. They have bought say 3 things & they get through the tills & oh they haven't got enough money. They know how much they have but didn't check to see what the total was going to be & even worse is the one that does have enough cash & says I don't want the change. I heard one checkout person explain that this money was going in the till & would inflate the bosses profits. So!

It doesn't bode well for any of their financial futures & anything which helps this MUST be a good thing.

reeac

SWMBO and I went to a quiz a week ago - we very seldom indulge in such things but it was for a charitable cause. One question required you to divide 60 by a quarter and then add 7. The concept of dividing by a quarter caused great consternation amongst a pretty well heeled audience.

Smodlet

National_Numeracy wrote: »

For money savers, the cost of heating your home is always a hot topic (pun intended). But for those with patchy maths skills, understanding the charges can be a bit of a nightmare.

At National Numeracy we want to help people understand the maths behind the charges, so we thought we'd ask for MSE users' help in explaining the numbers.

So, in that spirit - how would you work out the question below? What aspects of numeracy would you use to arrive at your conclusion?

If you use 11,650 kWh of gas a year, what is a sensible amount for a monthly direct debit?

Gas Tariff:
4.0p per kWh
Standing charge 22p/day

What a brilliant topic, imho! It being the first of the month, I have just been doing exactly this for my own usage so I know precisely (calorific value fluctuations notwithstanding) how much credit I have left.

11650 kwh x (multiplied by) 0.04 pence (unit price) = £466 for gas usage

Standing charge = 365 (days in a year) x (multiplied by) 0.22 pence = £80.30

Add them together and what have you got? £546.30 cost for the year, divide this by 12 months in the year = £45.53, normally rounded up to the nearest whole £ = £46 per month, assuming prices quoted include V.A.T.

If V.A.T. is not included, £546.30 x (multiplied by) 5% = £27.32, add this to £546.30 = £573.62 divided by 12 months = £47.80 so £48 per month DD.

As has been mentioned, the conversion to kwh is already done in this instance but, for those of us still on an antediluvian meter in 100s of cubic feet, the conversion formula should be on your bill. I have it down, now: meter reading subtracting previous meter reading multiplied by 2.83, multiplied by calorific value typically 39.5, multiplied by 1.02264 divided by 3.6 = kwh.

A grade 'O' Level maths... No idea what BODMAS is! :eek:


ETA: 4 pence per kwh for gas is astronomical, imo. Compare and switch, already, armed with the knowledge to work out for yourself how much you will save as the CEC can only go on average usage.

Smodlet

Shrimply wrote: »

Only if you are given a mathematical problem written in that format to solve. Not if you have to solve real life issues dealing with numbers. Knowing the rules doesn't help you write the problem down following the convention correctly either unless you are thinking about why you are doing it and what it means.

This is the difference that people don't seem to grasp. We can easily give children work sheets with lists of problems to work through following the rules that we detail. But that doesn't do anything to teach critical thinking.

... Doesn't sound as if it does much to teach them maths either which, in a maths lesson, is surely the point? If "critical thinking" were correctly applied in the situation Hengus described, your students would not get to the till without knowing they had tried to buy more than they could pay for. No wonder employers complain about the woeful lack of numeracy (and literacy) skills in young job applicants.

NineDeuce

(11650 x 0.04) + (365 x 0.22) = yearly cost. Divide by 12