Maths Marking

c_f_p99 · 28-06-2019 8:46pm #1

The marking scheme says that if there is an arithmetic slip or a misreading in a question, one mark is deducted. What if there are multiple slips and/or misreadings? What would happen then?

Postgrad10 · 28-06-2019 11:03pm

Are you an examiner doing this years scripts or are you just looking over past examples?

c_f_p99 · 29-06-2019 9:29am

No, just looking over past examples.

Postgrad10 · 29-06-2019 9:59am

Good. Was going to say don’t be frightened to ask the advising examiner if you are stuck.

You could maybe email/ message the maths teachers association http://www.imtadublin.com

One of them is bound to have marked at some stage.

loveroflight · 01-07-2019 1:00pm

HI=i c_f_p99

I believe from reading the past marking schemes that if you make two slips within the one question, its counted as one slip. But this can occur again in another question.

Hope all goes well in August.

c_f_p99 · 08-07-2019 2:18pm

Okay to make things clear, I'm just a student, going into 6th year.

c_f_p99 · 08-07-2019 2:21pm

loveroflight wrote: »

HI=i c_f_p99

I believe from reading the past marking schemes that if you make two slips within the one question, its counted as one slip. But this can occur again in another question.

Hope all goes well in August.

Wow, that seems to be really generous. I thought that you'd be down to the high partial credit as a result (which is very reasonable in itself).

c_f_p99 · 18-07-2019 2:13pm

For example, I wrote log10* - log10*100 = -10. A really stupid mistake, I know, but I got deducted a partial credit for that (only got 10 out of 15 marks). Isn't that an arthimetical slip? I probably should have simplified that to -log10*100 then made it equal to whatever, but should it count as a slip or a partial credit?

B_ecke_r · 18-07-2019 2:16pm

there's no double marking on a question AFAIK

example - if you get the wrong slope for a equation - but get the right answer based off your incorrect slope, you're only marked down once?

Correct?

c_f_p99 · 18-07-2019 2:45pm

That's not the question though, it's whether my mistake deducts 1 mark for a slip or 5 marks down to the partial credit.

c_f_p99 · 18-07-2019 2:46pm

B_ecke_r wrote: »

there's no double marking on a question AFAIK

example - if you get the wrong slope for a equation - but get the right answer based off your incorrect slope, you're only marked down once?

Correct?

I don't understand what you mean by correct answer, you'd end up with the wrong one surely. I think you mean the whole working out which I'd say you're only marked down once.

B_ecke_r · 18-07-2019 8:50pm

c_f_p99 wrote: »

I don't understand what you mean by correct answer, you'd end up with the wrong one surely. I think you mean the whole working out which I'd say you're only marked down once.

But it would be the correct answer using the incorrect slope of that makes sense ?

c_f_p99 · 19-07-2019 12:34pm

B_ecke_r wrote: »

But it would be the correct answer using the incorrect slope of that makes sense ?

I'm sorry, I don't know what you mean. Can you tell me the whole question so I can get a better idea of what's going on?

scout353 · 19-07-2019 2:25pm

c_f_p99 wrote: »

I'm sorry, I don't know what you mean. Can you tell me the whole question so I can get a better idea of what's going on?

If you make a computational error it is a slip and if you use that result (even though it is wrong) but continue your question with the correct method and answer using that result you would receive your marks.

c_f_p99 · 19-07-2019 2:44pm

scout353 wrote: »

If you make a computational error it is a slip and if you use that result (even though it is wrong) but continue your question with the correct method and answer using that result you would receive your marks.

Yes, I know that, but does my mistake merit a slip or down to a partial credit is my question. It's strange how confusing the scheme is for Maths.

Moody_mona · 19-07-2019 6:01pm

c_f_p99 wrote: »

For example, I wrote log10* - log10*100 = -10. A really stupid mistake, I know, but I got deducted a partial credit for that (only got 10 out of 15 marks). Isn't that an arthimetical slip? I probably should have simplified that to -log10*100 then made it equal to whatever, but should it count as a slip or a partial credit?

What were you supposed to have written?

A slip is if you misread a figure in the question without simplifying the work involved. A slip is if you make an arithmetic slip like 5 x 6 = 35. An error (not a slip) is when you say 10^2 is 20 (I know this seems like an arithmetic slip but it shows an error understanding squaring).

I don't understand what your log example is meant to be, can you take a picture of the question and your attempt?

c_f_p99 · 19-07-2019 6:04pm

Moody_mona wrote: »

What were you supposed to have written?

A slip is if you misread a figure in the question without simplifying the work involved. A slip is if you make an arithmetic slip like 5 x 6 = 35. An error (not a slip) is when you say 10^2 is 20 (I know this seems like an arithmetic slip but it shows an error understanding squaring).

I don't understand what your log example is meant to be, can you take a picture of the question and your attempt?

I simply should have written -2 as the answer. I miscalculated that final figure to be -10. Interesting as I thought that logarithms are part of arithmetic as are indices. Okay, good to note that.

Moody_mona · 20-07-2019 11:53pm

Arithmetic slip doesn't mean a mistake under the heading of arithmetic, it means a calculation error. You can have an arithmetic slip in a coordinate geometry question for example.

Based on my understanding of your example, you would drop a credit level, so if everything else was correct you would probably get high partial credit. You'll notice the marking scheme will say things like two correct steps or writes _______ and stops etc. To make an arithmetic error in a log question you'd have to have written something like:
Log5 + log 3 = log (5*3) = log12
Here it's clear to the examiner that you understand log rules but have somehow managed to get 12 when multiplying five by three.
Any other mistake is an error.

c_f_p99 · 21-07-2019 9:36am

What I did was a calculation error though. I thought that it applied to the laws of logs and all that. I didn't misuse a law, I just miscalculated -log10*100 to be -10. Are you sure that it's not an arithmetic slip? Look, I think that it's very fair of the examiner to drop me to the high partial for that question, it's just that I always that a miscalculation like that would be an arithmetic slip since it's clear that I understand logs for example. It's something you can just bash on a calculator, just like addition, multiplication, etc.

Thank you very much for that, but are you sure that that doesn't fall under arithmetic slip?

c_f_p99 · 21-07-2019 9:37am

Maths is the nicest marked paper in the LC anyway, so I'm not mad with the decision, just wondered whether they could have been even nicer to me.

c_f_p99 · 21-07-2019 9:50am

Okay, so arithmetic slips only happen for addition, subtraction, multiplication and division. Not for exponentiation and logarithms? That's something to take note, gonna be extra careful when dealing with the latter two (always going to evaluate exponents and logs on the calculator, although I will try for all six of them).

Moody_mona · 21-07-2019 12:56pm

I'm on mobile so maybe the desktop version of your log question looks better, I presume you said that - log to the base ten of 100 equals -10 when you should have said -2. The problem here is that you didn't make an accidental arithmetic slip. Instead you said to yourself 10 by 10 is 100 therefore the answer is -10; when you should have said 10^2 is 100 therefore the answer is -2. That's not a minor calculation slip or a computation slip. It's an error in your understanding of indices and logarithms.

My advice would always be to use your calculator. It's great to estimate or think through a sum first, and then back it up with a calculator.

c_f_p99 · 21-07-2019 2:10pm

Moody_mona wrote: »

I'm on mobile so maybe the desktop version of your log question looks better, I presume you said that - log to the base ten of 100 equals -10 when you should have said -2. The problem here is that you didn't make an accidental arithmetic slip. Instead you said to yourself 10 by 10 is 100 therefore the answer is -10; when you should have said 10^2 is 100 therefore the answer is -2. That's not a minor calculation slip or a computation slip. It's an error in your understanding of indices and logarithms.

My advice would always be to use your calculator. It's great to estimate or think through a sum first, and then back it up with a calculator.

Okay, fair enough. I thought that anything that can be done on a calculator counts for an arithmetical slip (such as sin78= wrong answer I thought would also get -1). It's kind of strange how they care more about evaluating logs, indices and trig numbers than addition, subtraction, multiplication and division since they are all equally easy to just compute onto a calculator.

So finally the arithmetic error only covers add, sub, multi and div, right? And the misreading -1 only happens if the whole method is more or less the same (just with the misread question). Also what happens if more than one slip or misreading occurs? Or if an slip and a misreading occurs?

I find it nice enough that they even have cases like that where only 1 mark is taken from you.

Moody_mona · 21-07-2019 2:33pm

I understand what you're saying than anything that can be typed into a calculator can count as an arithmetic slip but to get -10 as the answer in your log question you would have had to type in something completely different, so it definitely wasn't a misread or a little mistake on your calculator; it was a misunderstanding.

The sine thing could count as a slip depending on the situation. For example if you were asked to find sin78 but you accidentally typed in sin87 that would count as a misread. Or if you were in rad or grad accidentally, that would be a -1 too.

When you're marking you give an asterisk when you see one of these slips. Misread, arithmetic slip, incorrect rounding, no unit. If you get more than one asterisk you drop a credit level. The asterisk only applies to fully correct question, which means you can't get a -1 on a low partial answer; your slip is just ignored.

Yes an arithmetic error is just a simple calculation error from one of the four operations.

c_f_p99 · 21-07-2019 3:29pm

Moody_mona wrote: »

I understand what you're saying than anything that can be typed into a calculator can count as an arithmetic slip but to get -10 as the answer in your log question you would have had to type in something completely different, so it definitely wasn't a misread or a little mistake on your calculator; it was a misunderstanding.

The sine thing could count as a slip depending on the situation. For example if you were asked to find sin78 but you accidentally typed in sin87 that would count as a misread. Or if you were in rad or grad accidentally, that would be a -1 too.

When you're marking you give an asterisk when you see one of these slips. Misread, arithmetic slip, incorrect rounding, no unit. If you get more than one asterisk you drop a credit level. The asterisk only applies to fully correct question, which means you can't get a -1 on a low partial answer; your slip is just ignored.

Yes an arithmetic error is just a simple calculation error from one of the four operations.

Interesting. I didn't use a calculator full stop for that question, though, if I had, this wouldn't have happened. It was just carelessness, I've never made anything like that before. Though, yes, I can see how that answer could have been interpreted as a misunderstanding, but it was just carelessness.

Thank you so much for that explanation. I've been trying to get an explanation of this for months. It would really help to have an understanding of that going into the exam since I would be able to prioritise which things I should look over more vigilantly than others. The lesson learned here is to always use a calculator when looking over answers.

Moody_mona · 21-07-2019 3:43pm

You're very welcome. Any time.

I think having a rough idea of an answer but then backing it up with the calculator is the best combination. In fairness if you had done that with this question you would have had -10 in your head, then gotten -2 on the calculator and you would have had this moment of internal dialogue where you made sense of it. You definitely wouldn't have made a power error elsewhere in the paper because you'd have been overly aware of it. Don't get too cocky or over confident, there's no shame in using your calculator, especially in a stressful exam situation. It's be a shame to know all you log rules etc and then mess it up with a simple calculation.

Maths Marking

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