Looks like there are multiple interpretations haha.
Regarding the logic point raised by Yertle, where would this extend to? Is it just discrete figures, eg. 4 molecules x 4molecules is 16 molecules, as we know that we have 4 and 4.5 molecules?
And darkz, if we have 1.1 - 1.05 = 0.05, would we not need to round our answer to 1 do, since we use decimal places for addition subtraction and not significant figures?
About the data book, what I mean is, that if we assume that Avogadros number is 6.02 x10^23, and that this is 100% accurate, we would not need to consider sig figs for this, since we know that it is exactly 6.02 x 10^23. My understanding is that we use sig figs for when we dont know the level of accuracy of a particular (continuous) quantity.
So much concern for just 1 mark on the exam. :/