$1\text{ km}=1000\text{ m}1\backslash km=1000\backslash m$

$8\text{ km}8\; \backslash km$ = $8000\text{ m}8000\backslash m$

$1{\text{ cm}}^2=100{\text{ mm}}^{2}1\backslash cm^2=100\backslash mm^2$

$\mathrm{3,12}{\text{ cm}}^{2}3\{,\}12\; \backslash cm^2$ = $312312$${\text{ mm}}^2\backslash mm^2$

$60\min =160\backslash min=1\backslash$h

$150150$ min = $\mathrm{2,5}2\{,\}5$ h