The Student Room Group

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Reply 1
The best way to stop silly mistakes is to do a question twice, but the second time completely forget that you've already done it. It's very easy to 'go over your working' while having your initial solution in the back of your mind, and you'll probably just reincorporate the same silly mistake.
Reply 2
My QM supervisor recommended checking each line as you go. ie Do a line, check it, do a line, check it..
Go over the paper at the end. I must have saved myself at least 8 marks when I did that in the November exams, I'd never done it before, only flicked through. But I actually went back and re-worked out everything and kept finding silly mistakes, so the teachers are actually right, it is worth doing.
Reply 4
Rework the exam at the end.

I do that too. The most embarrassing is when you write the correct answer and then write a wrong answer 1 line down and triple underline it. When you look at the exam you get back it's just :facepalm:
Reply 5
Original post by SimonM
My QM supervisor recommended checking each line as you go. ie Do a line, check it, do a line, check it..


This is definately the best way.
Reply 6
As everyone else has said, go over it, line by line. Working backwards from a solution works too (eg. if you are trying to find x, substitute x into the beginning equation and see if it works). If something doesn't seem right, do the question again like you never even attempted it the first time.

Other than that, just try to remember every little trick. Remember to find both the positive and negative roots of quadratics. Remember +C when intergrating (the number of times my teacher has had a go at me for forgetting :colondollar:), double roots where the line just touches x, drawing graphs REALLY helps, especially with wordy questions, inequalities etc.

I too am doing C1 I'm good at maths, but I make lots of silly mistakes like you. I'm getting much much better though because I remember to check and check again, it really does help.
(edited 13 years ago)
Check, check and check again!

I always worked solutions backwards as I found while going forward I wouldn't notice the mistake!
Same as everyone else is saying. I tend to recover a third of my marks in maths from it...>_>
Pretty much what's been said already covers everything, but I'll add my two cents with some 'common sense' checks.

Coordinate Geometry:
If you're finding the equation of a line, is your gradient positive or negative? Which did you expect it to be? If it's a rising line and you have a negative gradient, you'll want to check your answer for missed minus signs. Remember the difference between a tangent and a normal.

Simultaenous Equations:
Put your values for x and y back into the equation, and see if they work.

Inequalities:
Almost all of the mistakes you can make on an inequalities question can be removed by DRAWING THE GRAPH. Also remember that multiplying or dividing by a negative number will change the orientation of the inequality. ( > becomes <, and viceversa).

Solving Equations:
As with simultaenous equations, sub your answer into the original equation to check it.
If you're dealing with a disguised quadratic don't forget that after you solve the equation you still need to find x from whatever variable you used as a 'disguise'. (E.g. x = t^(1/2) - you still need to find x after getting t)

Differentiation
Don't panic if you're faced with something horrible looking, the rules are still the same!
Rewrite fractions where x is the denominator so that they're in power form (Remember, x^-n = 1/x^n)
Same principle for square roots, write them as fractional powers.

General Advice:
It can be tempting to try and do large leaps of working in your head if you're confident. If you do, make sure you write the question the 'long way' when you're checking, minus signs have a horrible tendancy to appear occasionally!

If you factorise something, multiply it back out to check it.

Remember that you *can* have a negative discriminant; it just means there are no real roots.


...Think that's me done. Can't remember the C1 syllabus particularly. Brain is full of horrible Fourier Transform-y stuff for Uni. :frown:
(edited 13 years ago)
Reply 10
Original post by Saf94

Original post by Saf94
I was doing some past papers for my C1 exam and i got 61 out of 75 mostly all were silly mistakes. I was wondering if anyone had any tips or could tell me if they made silly mistakes in their actual exams, i'm hoping when i go into the exam that i'll stop making these mistakes. Any advice or feedback would be marvellous :-)


What are you calling a 'silly mistake'?
Personally I found a lot of silly mistakes I had made in C1 when I went over it, I must have found them all because I got 100% but the point is you need to learn the types of mistakes you typically make, and if there is a different possible way to do a question do that to check, less likely to just be persuaded by your own working.
Reply 12
Original post by SimonM

Original post by SimonM
My QM supervisor recommended checking each line as you go. ie Do a line, check it, do a line, check it..


There's probably some interesting psychology here. I'm wondering if the reasons for the mistakes made in QM-like manipulation are the same as those for mistakes made in basic manipulation. Whenever I do something like solving a quadratic, or solving a simultaneous equation, it feels like a fundamentally different task from large line-to-line rearranging. Hmm? :dontknow:
Reply 13
Original post by Kolya
There's probably some interesting psychology here. I'm wondering if the reasons for the mistakes made in QM-like manipulation are the same as those for mistakes made in basic manipulation. Whenever I do something like solving a quadratic, or solving a simultaneous equation, it feels like a fundamentally different task from large line-to-line rearranging. Hmm? :dontknow:


Possibly, but my errors were coming from algebraic manipulations, not solving things.
Original post by EEngWillow

General Advice:
It can be tempting to try and do large leaps of working in your head if you're confident. If you do, make sure you write the question the 'long way' when you're checking, minus signs have a horrible tendancy to appear occasionally!


Aargh this. I made a thread asking about mistakes yesterday, featuring things like '32' appearing in my answer when I'd squared 6, or managing to make 2-(-1)=1 - pathetic things like that. But for some reason when I checked it I just missed the mistakes. Douche. I think I've improved on it now; after I got my result from the mock (I got a B =/) I did a past paper, marked it and managed 72/72. :smile:

Another plan is to check the multiplying out stages; I normally manage to make a term just disappear. Try using the table method of doing it - makes it almost impossible to overlook terms.
Original post by Contrad!ction.
Aargh this. I made a thread asking about mistakes yesterday, featuring things like '32' appearing in my answer when I'd squared 6, or managing to make 2-(-1)=1 - pathetic things like that. But for some reason when I checked it I just missed the mistakes. Douche. I think I've improved on it now; after I got my result from the mock (I got a B =/) I did a past paper, marked it and managed 72/72. :smile:


My personal favourite mistake was during my M1 a couple of years ago, where my very first line of working was to write that (3x)^2 = 9x.

Seriously, I could understand the mistake of writing 3x^2, but squaring the coefficient and forgetting about the x? Wtf happened that day I will never know! :o:p
Original post by EEngWillow
My personal favourite mistake was during my M1 a couple of years ago, where my very first line of working was to write that (3x)^2 = 9x.

Seriously, I could understand the mistake of writing 3x^2, but squaring the coefficient and forgetting about the x? Wtf happened that day I will never know! :o:p


:biggrin: Nicely done :tongue:

Not Maths but Physics - I decided that I'd multiply one of my numbers by 2 for no reason.

Oh, another tip for mistakes:
RTFQ!
Reply 17
Original post by SimonM
My QM supervisor recommended checking each line as you go. ie Do a line, check it, do a line, check it..
I think the advantage which this has over doing the question twice is that, if you do it twice and get different answers you have to do it a third time, which is a waste of time. Also, doing twice is probably impractical for non-basic questions, specially during an exam, and rechecking each line would be more efficient. On the question, I remember reading somewhere that one of the reasons for which the Chinese team does so well in the IMO is that during the training they are expected to do ridiculous number of questions, which not only makes them better problem-solvers, but also eliminates the chances making silly/careless mistakes.
Reply 18
in order to do really well in math, you got to do lots of questions and really have to all sorts of questions the ways to solve. You just got to do questions honestly.
Well,first of all,it is very important to think twice before actions.
Morever, keeping making silly mistakes may be related to your character and temple.Are you always impatient with guys or foundations of things or unkind or something esle.Think it over,and you may get new ideas.:smile: