1. 直接写出得数。
$7.8 + \frac{1}{5} =$
$2.9 - 0.56 =$
$0.25 × 0.8 =$
$4.3 - 2.1 + 0.8 =$
$0.37 - 0.18 =$
$0.49 ÷ 0.7 =$
$9.7 - 0.97 =$
$6.4 ÷ 3.2 - 0.6 =$
$4.2 ÷ 0.3 =$
$0.24 × 0.5 =$
$0.4 ÷ 0.8 =$
$0.9 × 7 + 10.7 =$
$0.7 × 0.07 =$
$6.8 ÷ 0.2 =$
$8 × 0.75 =$
$6.8 - 2.4 ÷ 3 =$
$\frac{1}{15} ÷ \frac{1}{3} =$
$\frac{5}{11} × \frac{44}{15} =$
$\frac{25}{17} ÷ \frac{5}{3} =$
$\frac{1}{11} × 99 + \frac{1}{11} =$
$\frac{7}{5} ÷ \frac{7}{15} =$
$\frac{3}{4} ÷ \frac{3}{5} =$
$\frac{11}{28} × \frac{4}{33} =$
$\frac{7}{8} - (\frac{7}{8} - \frac{1}{8}) =$
$7 + \frac{3}{14} =$
$1 ÷ \frac{1}{5} =$
$\frac{8}{3} × \frac{9}{22} =$
$5 + \frac{2}{3} + \frac{1}{3} =$
$\frac{5}{36} × \frac{9}{20} =$
$\frac{19}{8} ÷ 19 =$
$\frac{4}{7} ÷ \frac{1}{21} =$
$(\frac{1}{2} - \frac{1}{8}) × 1.6 =$

1. $7.8 + \frac{1}{5} = 8$
$2.9 - 0.56 = 2.34$
$0.25 × 0.8 = 0.2$
$4.3 - 2.1 + 0.8 = 3$
$0.37 - 0.18 = 0.19$
$0.49 ÷ 0.7 = 0.7$
$9.7 - 0.97 = 8.73$
$6.4 ÷ 3.2 - 0.6 = 1.4$
$4.2 ÷ 0.3 = 14$
$0.24 × 0.5 = 0.12$
$0.4 ÷ 0.8 = 0.5$
$0.9 × 7 + 10.7 = 17$
$0.7 × 0.07 = 0.049$
$6.8 ÷ 0.2 = 34$
$8 × 0.75 = 6$
$6.8 - 2.4 ÷ 3 = 6$
$\frac{1}{15} ÷ \frac{1}{3} = \frac{1}{5}$
$\frac{5}{11} × \frac{44}{15} = \frac{4}{3}$
$\frac{25}{17} ÷ \frac{5}{3} = \frac{15}{17}$
$\frac{1}{11} × 99 + \frac{1}{11} = 9\frac{1}{11}$
$\frac{7}{5} ÷ \frac{7}{15} = 3$
$\frac{3}{4} ÷ \frac{3}{5} = \frac{5}{4}$
$\frac{11}{28} × \frac{4}{33} = \frac{1}{21}$
$\frac{7}{8} - (\frac{7}{8} - \frac{1}{8}) = \frac{1}{8}$
$7 + \frac{3}{14} = 7\frac{3}{14}$
$1 ÷ \frac{1}{5} = 5$
$\frac{8}{3} × \frac{9}{22} = \frac{12}{11}$
$5 + \frac{2}{3} + \frac{1}{3} = 6$
$\frac{5}{36} × \frac{9}{20} = \frac{1}{16}$
$\frac{19}{8} ÷ 19 = \frac{1}{8}$
$\frac{4}{7} ÷ \frac{1}{21} = 12$
$(\frac{1}{2} - \frac{1}{8}) × 1.6 = 0.6$

2. 计算下面各题，怎样算简便就怎样算。
$240÷1.6÷0.5$
$(15.5×6+8.5×6)×\frac{1}{8}$
$(8.1+2.32)×3.6-2.78$
$(56+\frac{8}{15})÷8$
$\frac{5}{12}÷\frac{8}{5}+\frac{5}{8}×\frac{7}{12}$
$(\frac{3}{4}-\frac{3}{4}×\frac{8}{9})÷1.5$

2. $240÷1.6÷0.5 = 300$
$(15.5×6+8.5×6)×\frac{1}{8} = 18$
$(8.1+2.32)×3.6-2.78 = 34.732$
$(56+\frac{8}{15})÷8 = 7\frac{1}{15}$
$\frac{5}{12}÷\frac{8}{5}+\frac{5}{8}×\frac{7}{12} = \frac{5}{8}$
$(\frac{3}{4}-\frac{3}{4}×\frac{8}{9})÷1.5 = \frac{1}{18}$

如果$\frac{1}{2}○2=\frac{1}{2}×\frac{1}{3}$，$\frac{1}{3}○4=\frac{1}{3}×\frac{1}{4}×\frac{1}{5}×\frac{1}{6}$，那么$\frac{1}{4}○4 - (\frac{1}{4}○5)=(\quad)$。

$\frac{1}{960}$