1 直接写出得数。(每题1分,共20分)
$\frac {7}{8}+\frac {1}{2}= $ $\frac {2}{7}+\frac {1}{14}= $ $\frac {3}{4}+\frac {1}{6}= $ $\frac {2}{8}+\frac {3}{8}+\frac {5}{8}= $
$\frac {1}{2}+\frac {1}{3}= $ $\frac {2}{3}-\frac {1}{6}= $ $\frac {1}{5}-\frac {1}{8}= $ $\frac {1}{14}+\frac {5}{14}+\frac {3}{14}= $
$\frac {1}{8}-\frac {1}{9}= $ $\frac {1}{12}+\frac {5}{12}= $ $\frac {1}{8}-\frac {1}{20}= $ $\frac {1}{4}+\frac {1}{4}+\frac {3}{4}= $
$\frac {3}{4}-\frac {1}{2}= $ $\frac {1}{2}-\frac {1}{7}= $ $\frac {5}{7}-\frac {3}{14}= $ $1-\frac {2}{3}-\frac {1}{3}= $
$\frac {11}{12}-\frac {7}{12}= $ $\frac {7}{25}+\frac {13}{25}= $ $\frac {7}{8}-\frac {5}{8}= $ $1-\frac {3}{8}-\frac {1}{8}= $

$\frac{11}{8}$ $\frac{5}{14}$ $\frac{11}{12}$ $\frac{5}{4}$
$\frac{5}{6}$ $\frac{1}{2}$ $\frac{3}{40}$ $\frac{9}{14}$
$\frac{1}{72}$ $\frac{1}{2}$ $\frac{3}{40}$ $\frac{5}{4}$
$\frac{1}{4}$ $\frac{5}{14}$ $\frac{1}{2}$ $0$
$\frac{1}{3}$ $\frac{4}{5}$ $\frac{1}{4}$ $\frac{1}{2}$

2 计算下列各题,能简算的要简算。(每题3分,共18分)
$\frac {1}{5}+(\frac {5}{6}-\frac {13}{18})$ $\frac {1}{2}+\frac {1}{3}-\frac {1}{4}$ $\frac {13}{15}-(\frac {13}{15}-\frac {2}{5})$
$\frac {5}{12}+\frac {3}{5}+\frac {7}{12}+\frac {2}{5}$ $\frac {5}{9}+(\frac {3}{4}+\frac {1}{2})$ $6-(\frac {8}{13}-\frac {5}{13})$

$\frac{14}{45}$ $\frac{7}{12}$ $\frac{2}{5}$
$2$ $\frac{65}{36}$ $\frac{75}{13}$

3 解方程。(每题4分,共12分)
$x-\frac {5}{6}= \frac {1}{6}$ $\frac {1}{6}+x= \frac {1}{2}$ $x-\frac {1}{2}= 0.25$

解：$x = 1$ 解：$x = \frac{1}{3}$ 解：$x = \frac{3}{4}$