Physics Significant Figures a level URGENT

So I saw this on the mark scheme:

"Answers to questions in the practical sections (7407/2 – Section A and 7408/3A) should display an
appropriate number of significant figures. For non-practical sections, an A-level paper may contain up to
2 marks (1 mark for AS) that are contingent on the candidate quoting the final answer in a calculation to
a specified number of significant figures (sf). This will generally be assessed to be the number of sf of
the datum with the least number of sf from which the answer is determined. The mark scheme will give
the range of sf that are acceptable but this will normally be the sf of the datum (or this sf -1)"

My question is, what do they mean by 'practical' and 'non-practical' sections?

Will they take into account the sig figs of my answers on all questions or only on those that tell me to 'give my answer in appropriate/certain number of sig figs'?

Reply 1

Ancience

Dont u just give the same s.f. as the numbers in the question unless it tells u otherwise

Reply 2

examjam

Original post by Ancience

Dont u just give the same s.f. as the numbers in the question unless it tells u otherwise

Yeah? But what if in the question they give you a datum of 1 sig fig, then would you still have to round your answer to 1 sig fig, even though, say, the exact value is '1456 years'?

Reply 3

Ancience

Original post by examjam

Yeah? But what if in the question they give you a datum of 1 sig fig, then would you still have to round your answer to 1 sig fig, even though, say, the exact value is '1456 years'?

1456 years would then be 4 s.f.

Reply 4

jack3473

Original post by examjam

Yeah? But what if in the question they give you a datum of 1 sig fig, then would you still have to round your answer to 1 sig fig, even though, say, the exact value is '1456 years'?

They only allocate a very small portion of marks per exam to sig figs. Try to give it to the same number as in the question, but even if you somehow manage to fail by following that rule of thumb you'll only be penalised one or two marks in the entire paper.

I'd focus on ensuring that you know all the challenging content you'll be tested on instead... electricity was a particular bugger in the AQA AS paper this year.

Reply 5

BTAnonymous

Original post by examjam

Yeah? But what if in the question they give you a datum of 1 sig fig, then would you still have to round your answer to 1 sig fig, even though, say, the exact value is '1456 years'?

can't go wrong with 2 sig fig for a question like that.

My advice would be to write down the value at least 1 more sig figs more than required in your working. This just shows the examiner what you've rounded to and could get you the marks. So if it asked for 3 sig fig (or give you answer to an appropriate sig fig) then show in your answer in your workings at least 4/5 significant figures.

Sig figs marks are unfair I think and it's quite hazy.

Reply 6

Graphittte

Practical means the practical paper you will sit (Paper 3A) assuming you're with AQA. Usually appropriate is to the lowest number of significant figures of any of the data you use. (As so i've been told, bit confused with this part of the paper still tbh)

In the non practical paper of course give your answer to the number of sf. that the question tells you to, and if it doesnt then again use the lowest amount of sf used in data you're given (this is usually 2 or 3, usually 2 is fine as you can see they allow 1 less sf than the amount given in the data, so generally you use 2).

Reply 7

16latimiah

Original post by graphittte

practical means the practical paper you will sit (paper 3a) assuming you're with aqa. Usually appropriate is to the lowest number of significant figures of any of the data you use. (as so i've been told, bit confused with this part of the paper still tbh)

in the non practical paper of course give your answer to the number of sf. That the question tells you to, and if it doesnt then again use the lowest amount of sf used in data you're given (this is usually 2 or 3, usually 2 is fine as you can see they allow 1 less sf than the amount given in the data, so generally you use 2).

thank you

Reply 8

sandrasandi

this is kinda old but what do i do if the question doesnt state the amount of significant figures needed and there's no other data points to go off of? you're meant to use values you already know, one of them is 1.6*10^-19 the other is 1.67*10^-27