Regarding Significant Figures and Decimel places

[jasopan]

Whenever I do a question, I always keep ALL calculations,
During working out I write 3 decimal places. (but obviously if it's something like 0.0001234 -I'll keep the 4 in case) and still use the whole number (all decimals).
And my final answer is with 2 decimal places so (e.g. 123.67N) and I try to keep that no matter what

Regarding worked solutions of some practice papers, they (especially the Gravity type questions) tend to round of rather early and only use those values, thus my answer is off by quite a bit at times (e.g. my last question was off by 10km where the answer was roughly).

I was wondering if I should continue to do what I've done, any suggestions? Cheers

[ks04]

As a general rule,
If the question has 2 figures in the wording i.e. 20N, then you goto 2 sig figures ie 8.3x10^6
If it has 3, then goto 3 i.e 8.34x10^6

[cameron_15]

They don't take marks off for significant figures. As long as you use the right formulas and make logical substitutions you should get full marks. Provided your answer is reasonable!