For problems where all the information is given in, let's say, 3 significant figures, should obtained data be rounded to 3 significant figures? For example, if I am doing Gibbs calculations and I am given a value of enthalpy and entropy in 3 sig figs, but my calculator spits out of a result which is in 4 sig figs, do I round that to 3 sig figs and then use that result for the future calculations?

It seems to especially matter when calculating the reaction constant K from [tex]K = \exp{\left(-\frac{\Delta G^\circ}{RT}\right)}[/tex] where small differences in rounding of the RHS values can alter the result quite significantly. For example, 4*10^{100} is a numerically speaking a much bigger number than 3*10^{100}, so it must have some importance (although the same can't be said for large, negative exponents). I understand that it might not make a huge difference in this context, but I'm wondering what is generally considered good practice.