\frac{1,6-\frac{2}{3}}{1,6*\frac{2}{3}}=\frac{1\frac{6}{10}-\frac{2}{3}}{1\frac{6}{10}*\frac{2}{3}}=
=\frac{1\frac{3}{5}-\frac{2}{3}}{1\frac{3}{5}*\frac{2}{3}}=\frac{\frac{8}{5}-\frac{2}{3}}{\frac{8}{5}*\frac{2}{3}}=
=\frac{\frac{24}{15}-\frac{10}{15}}{\frac{16}{15}}=\frac{\frac{14}{15}}{\frac{16}{15}}=\frac{14}{15}*\frac{15}{16}=\frac{7}{8}