2 4/9-1 5/6;

$$2 \frac{4}{9} - 1 \frac{5}{6} = 2 + \frac{4}{9} - 1 - \frac{5}{6} = 1 + \frac{4}{9} - \frac{5}{6} = 1 + \frac{4 \cdot 2}{9 \cdot 2} - \frac{5 \cdot 3}{6 \cdot 3} = 1 + \frac{8}{18} - \frac{15}{18} = 1 - \frac{7}{18} = \frac{18}{18} - \frac{7}{18} = \frac{18-7}{18} = \frac{11}{18}$$

Ответ: $$\frac{11}{18}$$