Firstly, let's rewrite the number in scientific notation.
Both numbers have its hiehgts non zero number in the first decimal place, which means that the power of 10 will be -1 for both:
[tex]\begin{gathered} 0.396=3.96\times10^{-1}^{} \\ 0.5=5\times10^{-1} \end{gathered}[/tex]
However, as we can see, the number 0.5 ended up with only one significant figure. After the division, we have to approximate to the lowest significant figures between the two involved in the division, so the result will only have 1 significant figure.
The division is:
[tex]\frac{3.96\times10^{-1}}{5\times10^{-1}}=\frac{3.96}{5}\times\frac{10^{-1}}{10^{-1}}=0.792\times1=7.92\times10^{-1}\approx8\times10^{-1}=0.8[/tex]
