Keep making algebraic mistakes - any advice? (1 Viewer)

[dannyo1]

Hey everyone, so maths advanced HSC in a few weeks and I'd like some advice before then. So basically, I understand most of the concepts in the course pretty well - like I get what a question is asking me to do at any given point, but when I complete it I very regularly make silly mistakes when doing algebra, factorising, simplifying etc etc. I've done a shit ton of past papers and am continuing to do em, and whilst this does help, I feel like I just keep making these kinda basic errors whilst having a good understanding of the overarching mathematical concepts, and it's bloody infuriating.

Any tips?

 

[laterz laterz]

Bro same. Like all my concepts are clear and whenever I do past papers, I get most of it right until I realise I did the dumbest silly mistakes. I have had this problem since primary school and it pisses me off sm. So what I am thinking about doing for HSC is that I finish the paper as fast as I can and then go over it thoroughly once I am done and check for any dumb errors I might have done. I feel like this is the only thing I can do at this point. Anyways, let's hope we don't make any mistakes in the HSC haha. Good luck

 

[jazz519]

Slow down and be more careful with your steps is the first thing. Rushing it can cause the mistakes.

Also practicing more doesn't mean you are going to reduce your silly mistakes. If you keep doing the same mistakes over and over the practice is what is causing you to do it because you are consistently applying the same approach to getting through the exam. So instead you need to try practice outside the exam with exam technique that reduces silly mistakes and so you can replicate that in the exam.


Also, check your answer quickly before you go to the next question. A major check you can do at the end if you finish with enough time but there are small things you can do along the way.

For example, if a question said solve x^2 + 2x + 1 = 0
and you make a silly mistake and lets say get x = 2, x = -3 somehow

Then you can check your answer is correct. Sub the number you got as answer back into the original expression. If it doesn't match up on the left and right sides then you made a mistake somewhere.

So in this case (2)^2 + 2(2) + 1 = 9, which is clearly not equal to 0.


You can use this same logic for even questions that are to do with simplifying expressions.

For example, if a question said


and you did some mistake somewhere and ended up getting 4x^2 + 7y^2 + 3xy

You can check it. Just make up a value for the x and y and sub it in at the beginning expression and the end one you simplified it to. These are things you do in your calculator btw to check.

Say you choose a random value for x = 2 and y = 5

(8x^3 - 27y^3) / (2x-3y) = (8*2^3 - 27*5^3) / (2*2-3*5) = 301

Sub now into your answer: 4x^2 + 7y^2 + 3xy
4(2)^2 + 7(5)^2 + 3(2)(5) = 221

This means there is a mistake in our algebra because the numbers should match since the first expression should just be a different form of the simplified one


For integration and differentiation, you can do the opposite operation and see what happens.

For example, if a question says differentiate y = 5x^3 - 2x

and we made a mistake and got dy/dx = 5x^2 - 2

you integrate that and you will get instead y = 5x^3 / 3 -2x

Highlighting a mistake


This type of thing can be applied to more complicated questions like the graph drawing ones where you need to find stationary points or inflexion point. Sub back in your value for x and if your dy/dx = 0 like it should for the max and min then some algebra error has occurred

 

[idkkdi]

Bro same. Like all my concepts are clear and whenever I do past papers, I get most of it right until I realise I did the dumbest silly mistakes. I have had this problem since primary school and it pisses me off sm. So what I am thinking about doing for HSC is that I finish the paper as fast as I can and then go over it thoroughly once I am done and check for any dumb errors I might have done. I feel like this is the only thing I can do at this point. Anyways, let's hope we don't make any mistakes in the HSC haha. Good luck

This never works for me, as whenever I double check I still can’t see the errors.
A 99 atar guy told me to do exams under time conditions and record a list of any errors I make. If your more conscious about the errors your less likely to make them

when you check, it's often quite hard to find errors.
there's a special tactic if you're a speed monster.

do the exam twice. when you do the same q again, you generally won't make the silly error again.

 

[tito981]

Hey everyone, so maths advanced HSC in a few weeks and I'd like some advice before then. So basically, I understand most of the concepts in the course pretty well - like I get what a question is asking me to do at any given point, but when I complete it I very regularly make silly mistakes when doing algebra, factorising, simplifying etc etc. I've done a shit ton of past papers and am continuing to do em, and whilst this does help, I feel like I just keep making these kinda basic errors whilst having a good understanding of the overarching mathematical concepts, and it's bloody infuriating.

Any tips?

slowing down

 

[dannyo1]

Hmm well given that there's no way I'm completing a 3 hour exam in 1.5 hours I'm gonna be looking at some of those other strategies hahaha. Main thing I'm gonna work on is subbing back answer into initial equation where that's possible. Hopefully that'll eliminate enough mistakes to have it not impact overall mark too much.

I would try slowing down, but I'm usually pretty pressed for time in maths exams so I'd really be pushing it if I was going through the steps much slower.

 

[tito981]

I would try slowing down, but I'm usually pretty pressed for time in maths exams so I'd really be pushing it if I was going through the steps much slower.

if your pushed for time in maths exams, become VERY good at the SIMPLE things. ie integration, differentation and graphing.

 

[dannyo1]

if your pushed for time in maths exams, become VERY good at the SIMPLE things. ie integration, differentation and graphing.

Yeah mate sounds good, this has actually been my biggest area of improvement since trials - although graphing tends to fuck me a little. Anyway, I'll figure it out lol.

 

[011235]

I do this quite a bit. if you're finishing the exam fast go back and do the questions backwards as quickly as possible. this gives you a fast but reasonable knowledge of whether a solution is correct. Very similar to what @jazz519 was saying

For example if it says differentiate XYZ integrate your solution or vice versa. Subbing in values using your calculator is also useful here.

Using this I've found that most of my marks lost are normally jumping over a step that I should have outlined or things where this strategy is difficult (eg combinatorics)

Also don't be afraid of using your calculator if you know your calculator well. The less thinking you have to do the less sillies you're going to make.

 

[dannyo1]

Also don't be afraid of using your calculator if you know your calculator well

Yeah I make extensive use of the verify mode as well as the memory functions. Verify is for if I'm worried that I've fucked up some simple log law or something and the memory works great when there's long ass formulae or messy numbers to be worked with.