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

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

② 计算。(每题3分,共18分)
$\frac{4}{5}-(\frac{2}{9}+\frac{4}{9})$
$\frac{1}{6}+(\frac{5}{6}-\frac{3}{8})$
$\frac{7}{12}-(\frac{7}{12}-\frac{4}{5})$
$\frac{1}{4}+\frac{1}{3}+\frac{1}{4}+\frac{2}{3}$
$\frac{9}{7}+\frac{1}{6}+\frac{5}{6}+\frac{5}{7}$
$2-\frac{3}{7}-\frac{4}{7}$

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

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

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