Significant figures

[Apink]

Sorry, this probably is the most asked question but do you base the amount of significant figures for your answer based on the information given overall or just the information you used for a certain question?
Eg. Resistance of LDR in daylight is 2kΩ but 25kΩ in darkness.
If you were asked the voltage drop in darkness, would you use one or two significant figures?
Also, do you have to consider the amount of significant figures in graphs?

[Apink]

Significant figures are not examined in physics unless they're stated.

For that question, I'd give it to 2 sig figs.
If someone gave it to 5 sig figs (e.g. 25000 ohms) they'd still get full marks.

And in graphs, it's stupid cause some graphs go like 1,2,3, etc. and then have. Point inbetween like 1.5 which forces you to go to 2 sig figs, just do whatever conveys your answer best to the examiner.

Significant figures are, ironically, not that significant to VCE physics.

Thanks for replying.
My teacher has been insisting we should have the right amount of significant figures as you would lose 1 mark for the whole exam no matter how many are incorrect. Is disregarding significant figures part of this new study design or is it a Physics thing?