# can you help me with this question please? i am new to A-level teaching. thanks

Discussion in 'Mathematics' started by worldcitizen, Sep 5, 2011.

1. ### worldcitizen

A mortgage is taken out for &pound;80,000. It is to be paid by annual instalments of &pound;5000 with the first payment to be paid at the end of the first year that the mortgage is taken. Out. the interest of 4% is charged on any outstanding debt. Find the total time taken to pay off the mortgage.

2. ### dydx

I'll get you started Mr Citizen and leave the fine detail for you to ponder over.

Amount owed at end of 1st year:

80000 x 1.04 - 5000 =

Amount owed at end of 2nd year

(80000 x 1.04 - 5000 ) x 1.04 - 5000 =
80000 x 1.04^2 - 5000 x 1.04 - 5000

3. ### cyolba

Actually, I think the OP is suggesting that the &pound;5000 is paide before the interest is charged, so there may need to be a slight adjustment to your figures, dydx...
However, I am worried that someone is teaching A-level Maths and unable to derive a solution to this type of problem.

cyolba, Geometric, but not Progressive

4. ### dydx

Fair comment, Cyolba, but if this is the case, the question appears flawed.

Mr Citizen - could you print the question as it appeared in the textbook/exam paper?

5. ### dydx

A bit harsh, Mr Cyoba. We were once mathematical pups in teaching A level maths. I know I was grateful for the support of more experienced teachers at the time.

6. ### AnonymousNew commenter

Of course, the question bears no relation to the real world of interest rate changes and daily charges. That would be much more interesting.

7. ### KarvolOccasional commenter

Support in how you teach something perhaps. Asking for help on something as basic as this when teaching A level is worrying.

8. ### GoldMathsNew commenter

If I remember rightly this question is from C2 and is NOTHING like any other question in the book, I used excel when I wanted to work it out however after working on it I think it can be solved by factorising out one of the values.

Try looking on CD for solution bank.

9. ### worldcitizen

Thank you. I did the same way but got 26 not 25 as the book suggested. At first I did not understand the question. I didn't realise that he pays exactly &pound;5000 every year. I thought the amouint he pays goes down every year.

10. ### rustybug

I have on several occasions found myself teaching an A-Level module that I am not ready for through no fault or choice of my own!
It is a reality in many schools that A-Level specialists move on and last-minute timetable changes involve a teacher inexperienced in A-Level (or very very rusty, or holding a non-maths degree, like me, with my B.Eng) thrust into the breach, either forced or strongly encouraged to do their best (in lieu of the alternative, which is sometimes nobody at all) with an unfamiliar A-Level module.
As a community we can all assist the students who have a teacher in this situation, by not making these sorts of "worrying that you can't even work that out" comments!
(Sorry to sound like a TES finger-wagger, but I was sparing a thought for the OP - GPs questions are the ones that sometimes confuse me, after a few years of teaching A-Level!!) (And I have always been able to count on unstinting support here, hope nothing's changed.)

11. ### dydx

Well said, rustybug.
It is assuring to know that we, as a mathematics community can help fellow collegues .

12. ### D Franklin

And you don't think this is worrying? I know that on the occasions I've had to teach something I'm not ready for it was worrying as hell!

I don't see the comments as meaning "If you can't do this you're ****, give up", but simply a warning that "If you are struggling with this, you are not (yet) in a good position for teaching the topic".

I would imagine that when you're stuck with teaching an unfamiliar module, you end up needing to learn the material (in your own time), while trying to stay one or two steps ahead of the class. In which I think feedback on whether you need to put it more work in an area is useful, but only if it's honest.

13. ### rustybug

It is worrying, but probably not helpful to say that to the person who is in that situation! A warning that "If you are struggling with this, you are not (yet) in a good position for teaching the topic" isn't the most constructive thing to offer someone after the start of term when they're probably on a speeding freight-train. As a community our best course of action is to offer unstinting assistance and encouragement to come back should more be needed!
The OP is obviously worried too, and is putting in the time and effort to address the situation.

14. ### worldcitizen

To put your minds at rest. I have maths degree and 23 years ago I got an A in my A level maths and been teaching maths since 1993. I believe everyone been in my position when they first started teaching A level.I just need to brush it up. I will be teaching C2 next term and getting myself ready for it. thanks for your support.

15. ### atics

Ignore any perceived 'criticism' - mathematics is a huge discipline and no-one can be expected to know all of it (especially those of us who devote most of our time to teaching); it comes down to what experience you've had of various topics. Even if you knew all the mathematics there was to know, which is obviously impossible, problem-solving such as your question can be tricky, and even experienced mathematicians can see the odd question and not know immediately how to answer it.
Good luck with your A-level teaching, and don't be put off asking for any further help you need. You could always pick on some of the more positive posters and send a private message if necessary. I know how important it can be to have someone you can go to with subject knowledge questions without being judged.

16. ### FlippantFlyer

worldcitizen: "A mortgage is taken out for £80,000. It is to be paid by annual instalments of £5000 with the first payment to be paid at the end of the first year that the mortgage is taken. Out. the interest of 4% is charged on any outstanding debt. Find the total time taken to pay off the mortgage."

What is really worrying, if this is how the original question was written, is that both you, and dydx failed to model a very basic question. I would have expected a strong NC level 6 student to have least modelled the question to the first iteration

17. ### brookes

Atics suggested that you Private Message people for help. I'd ask you (and others lurking) to post publicly. If all of the positive and supportive stuff goes under cover, we run the risk of the forum being dominated by the negative and cynical.

18. ### NazardNew commenter

To be fair, I had to read it several times to work out what it meant. In real life you pay interest on _all_ the money you have borrowed that year, and not just on the bit you haven't paid off.

19. ### atics

I agree with your argument, but I just would rather someone PM someone for help rather than feel they can't get access to help because they are too scared to post publicly.

20. ### rustybug

Shouldn't we as a community rather be trying to address the culture that leads posters to make people feel "too scared to post publicly"?