To what significant figure should a candidates use for their calculated quantities?

The correct number of significant figures should be the same as, or one more than the smallest number of significant figures in the data used in the calculation.

For example, if titre volume is measured to four significant figures, e.g. 23.45cm³, then the calculated molar concentrations from this should be given four significant figures, e.g. 1.305mol dm^-3 or 0.9876mol dm^-3. However, if the concentration of one of the reactants is given to three significant figures, then the calculated concentration could be given to three or four significant figures. For example, if the alkali concentration in an acid-base titration is given 0.100 mol dm^-3, then the concentration of acid may be shown as 0.1305 mol dm^-3 or 0.131 mol dm^-3.