\(6.25 \times 10^{-3} \mathrm{~kl}\)

\begin{aligned}
6250 \mathrm{~ml} &=6250 \div 1000 \mathrm{~l} \\
&=6.25 \mathrm{~l} \\
&=6.25 \div 1000 \mathrm{~kl} \\
&=0.00625 \mathrm{~kl} \\
&=6.25 \times 10^{-3} \mathrm{~kl}
\end{aligned}

\(4.8 \times 10^{4} \mathrm{~cm}^{2}\)

\begin{aligned}
1 \mathrm{~m}^{2} &=100 \times 100 \mathrm{~cm}^{2} \\
&=10^{4} \mathrm{~cm}^{2} \\
\therefore 4.8 \mathrm{~m}^{2} &=4.8 \times 10^{4} \mathrm{~cm}^{2}
\end{aligned}

\(6.02 \times {10^7}~\text{mg}\)

\begin{aligned}
60.2 \mathrm{~kg} &=60.2 \times 10^{3} \mathrm{~g} \\
&=60.2 \times 10^{3} \times 10^{3} \mathrm{~mg} \\
&=60.2 \times 10^{6} \mathrm{~mg} \\
&=6.02 \times 10^{7} \mathrm{~mg}
\end{aligned}

\(2.0 \times {10^{ - 5}}~\text{km}^3\)

\begin{aligned}
1 \mathrm{~km}^{3}=& 1000 \times 1000 \times 1000 \\
=&10^{9} \mathrm{~m}^{3} \\
20000 \mathrm{~m}^{3}&= 20000 \div 10^{9} \mathrm{~km}^{3} \\
&=2 \times 10^{4} \div 10^{9} \\
&=2.0 \times 10^{-5} \mathrm{~km}^{3}
\end{aligned}