1 直接写出得数。(每题1分,共20分)
$\frac {3}{10}+\frac {2}{3}= $ $\frac {3}{7}+\frac {4}{7}= $ $\frac {14}{15}-\frac {4}{15}= $ $\frac {4}{9}-\frac {1}{3}= $
$\frac {7}{8}-\frac {3}{4}= $ $1-\frac {7}{8}= $ $\frac {2}{3}+\frac {1}{9}= $ $0.25+\frac {1}{7}= $
$\frac {2}{5}+\frac {3}{10}= $ $\frac {5}{6}+\frac {3}{4}= $ $3\frac {1}{2}+3= $ $5÷6+\frac {1}{6}= $
$1-\frac {11}{15}= $ $\frac {1}{5}+\frac {1}{6}= $ $\frac {1}{2}-\frac {2}{5}= $ $0.2+\frac {3}{5}-\frac {4}{5}= $
$\frac {5}{12}-\frac {1}{4}= $ $\frac {5}{7}-\frac {1}{4}= $ $\frac {1}{5}+\frac {1}{8}= $ $1-\frac {4}{9}+\frac {5}{9}= $

$\frac{29}{30}$ 　1 　　$\frac{2}{3}$ 　　$\frac{1}{9}$　$\frac{1}{8}$ 　$\frac{1}{8}$ 　　$\frac{7}{9}$ 　　$\frac{11}{28}$　$\frac{7}{10}$ 　$\frac{19}{12}$ 　　$\frac{13}{2}$ 　1 　$\frac{4}{15}$ 　$\frac{11}{30}$ 　　$\frac{1}{10}$ 　0 　$\frac{1}{6}$ 　　$\frac{13}{28}$ 　　$\frac{13}{40}$ 　　$\frac{10}{9}$

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

$\frac{2}{15}$ 　$\frac{5}{8}$ 　　$\frac{4}{5}$　$\frac{3}{2}$ 　　3 　　　1

3 解方程。(每题4分,共12分)
$x-\frac {1}{6}= \frac {3}{12}$ $\frac {2}{9}+x= \frac {20}{27}$ $\frac {8}{9}-x= \frac {2}{3}$

解：$x=\frac{5}{12}$ 解：$x=\frac{14}{27}$ 解：$x=\frac{2}{9}$