4) \(5\frac{1}{4}\cdot\frac{2}{8}\)

Сократим дробь \(\frac{2}{8}=\frac{1}{4}\):

\(5\frac{1}{4}\cdot\frac{1}{4}=\frac{21}{4}\cdot\frac{1}{4}=\frac{21}{16}=1\frac{5}{16}\).

Ответ: \(1\frac{5}{16}\)