if you don’t say anything else, it means that the measure is done with a scales

if you don’t say anything else, it means that the measure is done with a scales that gave 0,1 g and for convention the misure can be between 0,5g and 0,7 g. In truth, to speak of error you should know the real valour of the measure. Without this you can speak only of precision ( the repetibility of a measure) or of sensibility (the number of the significant figures that the instrument can give). The % of precision is P % = ± 0.1 0.6 = ± 17 % Someone tells that if the effective value was for example 0,549 the instrument would mark 0,5g and the % of error could be E % = ± 0.05 0.6 = ± 8 % but i am agree with the first result