1. 直接写出得数。
9.6 - 0.4 =
1.9 + 0.8 =
2.01 + 1.9 =
2.9 + 0.3 + 1.6 =
0.7 + 2.3 =
2.6 - 1.7 =
1.8 ÷ 4 =
9.7 - 10.5 ÷ 5 =
2.3 ÷ 0.1 =
3.2 ÷ 1.6 =
0.9 ÷ 4.5 =
5.6 ÷ 0.4 - 1.8 =
9 × 0.08 =
2.4 × 30 =
4.3 × 0.02 =
2.3 × 0.1 ÷ 10 =
$\frac{7}{8} ÷ 35 =$
$1 - \frac{5}{13} =$
$\frac{3}{8} + \frac{3}{4} =$
$\frac{8}{15} ÷ 3 × \frac{5}{6} =$
$\frac{2}{7} × 5 =$
$\frac{5}{6} + \frac{5}{6} =$
$\frac{23}{100} ÷ 0.1 =$
$\frac{4}{5} + \frac{2}{3} + \frac{1}{5} =$
$\frac{4}{15} ÷ 0.25 =$
$\frac{1}{10} ÷ \frac{1}{200} =$
$\frac{5}{18} + \frac{2}{3} =$
$\frac{1}{9} × \frac{3}{2} × \frac{3}{4} =$
$\frac{3}{4} × \frac{1}{2} =$
$\frac{5}{9} × \frac{3}{4} =$
$\frac{3}{25} × \frac{5}{12} =$
$( \frac{3}{4} + \frac{1}{6} ) ÷ \frac{5}{8} =$

9.6 - 0.4 = 9.2
1.9 + 0.8 = 2.7
2.01 + 1.9 = 3.91
2.9 + 0.3 + 1.6 = 4.8
0.7 + 2.3 = 3
2.6 - 1.7 = 0.9
1.8 ÷ 4 = 0.45
9.7 - 10.5 ÷ 5 = 7.6
2.3 ÷ 0.1 = 23
3.2 ÷ 1.6 = 2
0.9 ÷ 4.5 = 0.2
5.6 ÷ 0.4 - 1.8 = 12.2
9 × 0.08 = 0.72
2.4 × 30 = 72
4.3 × 0.02 = 0.086
2.3 × 0.1 ÷ 10 = 0.023
$\frac{7}{8} ÷ 35 = \frac{1}{40}$
$1 - \frac{5}{13} = \frac{8}{13}$
$\frac{3}{8} + \frac{3}{4} = \frac{9}{8}$
$\frac{8}{15} ÷ 3 × \frac{5}{6} = \frac{4}{27}$
$\frac{2}{7} × 5 = \frac{10}{7}$
$\frac{5}{6} + \frac{5}{6} = \frac{5}{3}$
$\frac{23}{100} ÷ 0.1 = 2.3$
$\frac{4}{5} + \frac{2}{3} + \frac{1}{5} = 1\frac{2}{3}$
$\frac{4}{15} ÷ 0.25 = \frac{16}{15}$
$\frac{1}{10} ÷ \frac{1}{200} = 20$
$\frac{5}{18} + \frac{2}{3} = \frac{17}{18}$
$\frac{1}{9} × \frac{3}{2} × \frac{3}{4} = \frac{1}{8}$
$\frac{3}{4} × \frac{1}{2} = \frac{3}{8}$
$\frac{5}{9} × \frac{3}{4} = \frac{5}{12}$
$\frac{3}{25} × \frac{5}{12} = \frac{1}{20}$
$( \frac{3}{4} + \frac{1}{6} ) ÷ \frac{5}{8} = \frac{22}{15}$

2. 计算下面各题，怎样算简便就怎样算。
2.5×56 + 4.5×56
200 - (3.05 + $\frac{39}{20}$)×18
30.8÷[14 - (9.85 + 1.07)]
1 - $\frac{5}{8}$÷$\frac{15}{14}$ - $\frac{5}{12}$
($\frac{1}{6}$ + $\frac{3}{8}$ - $\frac{5}{12}$)×4.8
$\frac{2}{3}$×[($\frac{3}{4}$ - $\frac{1}{6}$)÷$\frac{1}{6}$]

2.5×56 + 4.5×56 = 392
200 - (3.05 + $\frac{39}{20}$)×18 = 110
30.8÷[14 - (9.85 + 1.07)] = 10
1 - $\frac{5}{8}$÷$\frac{15}{14}$ - $\frac{5}{12}$ = 0
($\frac{1}{6}$ + $\frac{3}{8}$ - $\frac{5}{12}$)×4.8 = 0.6
$\frac{2}{3}$×[($\frac{3}{4}$ - $\frac{1}{6}$)÷$\frac{1}{6}$] = $\frac{7}{3}$

一项工程，甲、乙两人合作8天完成，乙、丙两人合作6天完成，丙、丁两人合作12天完成，那么甲、丁两人合作多少天可以完成？

$1÷(\frac{1}{8}+\frac{1}{12}-\frac{1}{6})=24$(天)