what it bigger 40% of 90 or half of 80
\(p\%=\frac{p}{100}\\\\40\%=\frac{40}{100}=\frac{4}{10}=0.4\\\\40\%\ of\ 90=0.4\cdot90=\fbox{36}\\\\half=\frac{1}{2}=0.5\\\\half\ of\ 80=0.5\cdot80=\fbox{40}\\\\therefore,\ bigger\ is\ \boxed{half\ of\ 80}\)