1. Найдите значение выражения: 1) 18,4 + 9,77; 2) 15,7 − 3,48; 3) 5,2 · 0,25; 4) 3,33 : 3,7; 5) 2/3 + 5/8; 6) 8 5/12 − 6 7/20; 7) 5/6 · 3/20; 8) 2 5/8 : 7/32.

1. \(18.4+9.77=28.17\).
2. \(15.7-3.48=12.22\).
3. \(5.2\cdot0.25=1.3\).
4. \(3.33:3.7=33:37\).
5. \(\frac{2}{3}+\frac{5}{8}=\frac{16}{24}+\frac{15}{24}=\frac{31}{24}=1\frac{7}{24}\).
6. \(8\frac{5}{12}-6\frac{7}{20}=8\frac{25}{60}-6\frac{21}{60}=2\frac{4}{60}=2\frac{1}{15}\).
7. \(\frac{5}{6}\cdot\frac{3}{20}=\frac{15}{120}=\frac{1}{8}\).
8. \(2\frac{5}{8}:\frac{7}{32}=\frac{21}{8}\cdot\frac{32}{7}=12\).

Ответ: 1) 28,17; 2) 12,22; 3) 1,3; 4) \(\frac{33}{37}\); 5) \(1\frac{7}{24}\); 6) \(2\frac{1}{15}\); 7) \(\frac{1}{8}\); 8) 12.