The length, breadth and height of a rectangular block of wood were measured to be  l = 1213 ± 0.02cm, b = 816 ± 0.01cm and h = 346 ± 0.01cm.

Volume of block, V lbh = 
The percentage error in the volume is given by 
$$\begin{gathered} \frac{∆\mathrm{V}}{\mathrm{V}}\mathrm{x} 100=\left(\frac{∆\mathrm{l}}{\mathrm{l}}+\frac{∆\mathrm{b}}{\mathrm{b}}+\frac{∆\mathrm{h}}{\mathrm{h}}\right) \mathrm{x} 100 \\ =\left(\frac{0.02}{1213}+\frac{0.01}{8.16}+\frac{0.01}{3.46}\right) \mathrm{x} 100 \\ =\left(\frac{200}{1213}+\frac{100}{816}+\frac{100}{346}\right) \end{gathered}$$
= 0.1649 + 0.1225 + 0.2890 
= 0.58 % (rounded off to two significant figures)