One percent of four hundred is four, so half a percent is two. Two percent of eighty is \(0.02\times80=1.6\).

The difference is \(2-1.6=0.4\). The smaller percentage gives the larger amount here because it applies to a larger whole.

Answer

\(0.5\%\) of \(400\) is greater: \(2\) versus \(1.6\), a difference of \(0.4\).