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Hi, I'm Steve Jones and I ought to give you some tips on problem solving in mathematics.
My first tip is do it step by step. Don't try and jump over steps, don't try and do
the easy ones in your head, because particularly if you're doing it in examination the examiner
is one to go - will want to see what you're doing. Okay, so here is a problem V equals
is pi R squared H. Okay. So, this formula is actually the formula for the volume of
a cylinder. So, this is a fairly straightforward problem, but how do we actually go about doing
it? And the first thing we have to say is as I've said, step by step. So, if we're going
to do this, substitute in step by step for pi, so you can have three point one four two,
R squared. Well R squared we know is R times R, and it would be very tempting to just write
here four, but I'm tempted to write two by two, two times two, and then write H. The
six. At this stage, now is the time to just double check, have we got pi, yes, have I
got R, yes, squared, yes. I've got two. Have I got H? Yes. It's all there. At least I know
to this stage I'm right. Even if I make a mistake later, the examiner will say, oh all
right, he's just made a slip and we won't knock too many marks off. So the next is to
do the calculation and obviously three point one four two, I'm not going to do anything
with at the moment, but two times four we know is four and six is on the end, the reason
I'm doing it in this way is because these might not be simple two times two, it might
be complicated numbers. So write that stage, the final stage three point one four two,
four sixes are twenty-four, and then work out this result. Now this gets us to an answer
and we work out whatever the answer is. Somewhere around eighty, but I'm not really bothered
what the answer is, I'm interested in seeing what the process and so are people who look
at your solutions to problems. So make sure the process is clear. At this point, I should
be saying well, this is going to be about, well, call that twenty-five and call that
three. Three twenty-fives, seventy-five. Okay it's about seventy-five. At this point, if
I use a calculator to get the answer, I will check that my guess at seventy-five is somewhere
near the answer I get with a calculator. It's very easy to put something wrong in the calculator.
So when you're doing problem solving in mathematics, number one, do it step by step. Number two,
and you'll notice I'd already done this, I'd actually put a list of the different quantities
on the right hand side with their units. This is again something which is easy to check
at the end. So here we are, how to solve problems in maths and now get docked marks for bad
work.