express 3.2 as:
[tex]3.2=\frac{16}{5}[/tex]and 0.8, as:
[tex]0.8=\frac{4}{5}[/tex]Use the following formula:
[tex]\frac{a}{b}\div\frac{c}{d}=\frac{a\cdot d}{b\cdot c}[/tex]so:
[tex]\frac{16}{5}\div\frac{4}{5}=\frac{16\cdot5}{5\cdot4}=\frac{80}{20}=4[/tex]