\underline{S_{2} = 2 \cdot 0, 1 {cm}^{2} = 0, 2 {cm}^{2} = 0, 00002 m^{2}}

${\underline{S_2 = 2 \cdot 0,1\, \text{cm}^2 = 0,2 \, \text{cm}^2 = 0,00002\, \text{m}^2}}$

Error