The word expression can be express mathematically as follows
[tex]\begin{gathered} \frac{2^{-3}}{2^{-5}} \\ \end{gathered}[/tex]Since the division sign is involve, using law of indicies we subtract the powers as follows
[tex]\begin{gathered} \frac{2^{-3}}{2^{-5}} \\ 2^{-3-(-5)} \\ 2^{-3+5} \\ 2^2 \\ 4 \end{gathered}[/tex]