1. 直接写出得数。(12分)
$\frac {1}{4} - \frac {1}{5} =$ $\frac {2}{3} ÷ \frac {4}{5} =$ $\frac {3}{4} - \frac {1}{4} ÷ \frac {1}{2} =$
$3. 1 4 × 7 0 =$ $2. 4 × 0. 5 =$ $0. 4 × 7 × 0. 2 5 =$
$1. 5 × \frac {4}{5} =$ $\frac {5}{6} × \frac {3}{5} =$ $(\frac {1}{6} + \frac {1}{4}) × 1 2 =$
$7 ^ {2} =$ $6. 3 ÷ 0. 0 9 =$ $\frac {5}{1 4} + \frac {7}{9} + \frac {9}{1 4} =$

1. $\frac{1}{20}$ $\frac{5}{6}$ $\frac{1}{4}$ 219.8 1.2 0.7 1.2 $\frac{1}{2}$
5 49 70 $1\frac{7}{9}$

2. 计算下面各题，能简算的要简算。(8分)
$5. 7 2 - \frac {4}{7} + 2. 2 8 - \frac {3}{7}$ $\frac {8}{1 7} ÷ 1 6 + \frac {1}{1 6} × \frac {9}{1 7}$
$\frac {2}{3} + (\frac {5}{6} - \frac {3}{4}) ÷ \frac {3}{8}$

2. 7 $\frac{1}{16}$ $\frac{8}{9}$ $\frac{4}{3}$

3. 解比例。(6分)
$2. 7: x = 0. 9: 0. 6$ $x: \frac {1}{8} = \frac {1}{1 0}: \frac {1}{4}$ $\frac {1 . 7 5}{3} = x: 6$

3. $x=1.8$ $x=\frac{1}{20}$ $x=3.5$

二、填空题。(每空1分，共27分)
1. $ \frac{( )}{8}=($ ):20=0.75=30 $ ÷ $ ( )=( )%=
( )折

1. 6 15 40 75 七五