1.直接写出得数。（每题1★）
$\frac{3}{5} + 0 =$
$1 - \frac{5}{7} =$
$\frac{2}{9} + \frac{4}{3} =$
$\frac{1}{3} - \frac{1}{6} =$
$\frac{1}{2} + \frac{3}{8} =$
$\frac{1}{5} - \frac{1}{6} =$
$5 - \frac{1}{3} =$
$\frac{1}{2} - \frac{1}{4} =$
$\frac{2}{3} - \frac{1}{6} =$
$5 + \frac{1}{3} =$
$\frac{2}{5} + \frac{7}{10} =$
$\frac{7}{9} - \frac{3}{5} =$
$\frac{1}{4} + \frac{1}{3} =$
$\frac{2}{7} + \frac{8}{21} =$
$\frac{11}{12} - \frac{1}{6} =$
$\frac{4}{9} + \frac{1}{8} =$
$\frac{2}{3} + \frac{5}{9} =$
$\frac{3}{10} + \frac{2}{3} =$
$\frac{17}{26} - \frac{1}{2} =$
$\frac{4}{5} - \frac{3}{8} =$

1.$\frac{3}{5}$
$\frac{2}{7}$
$\frac{14}{9}$
$\frac{1}{6}$
$\frac{7}{8}$
$\frac{1}{30}$
$4\frac{2}{3}$
$\frac{1}{4}$
$\frac{1}{2}$
$5\frac{1}{3}$
$\frac{11}{10}$
$\frac{8}{45}$
$\frac{7}{12}$
$\frac{2}{3}$
$\frac{3}{4}$
$\frac{41}{72}$
$\frac{11}{9}$
$\frac{29}{30}$
$\frac{2}{13}$
$\frac{17}{40}$

2.计算下面各题,能简算的要简算。(每题3★)
$\frac{3}{5}+\frac{7}{10}+\frac{2}{5}$
$\frac{4}{3}-\frac{4}{7}-\frac{1}{3}$
$\frac{17}{16}-\frac{1}{4}-\frac{3}{8}$
$\frac{9}{10}-\frac{2}{5}-\frac{1}{4}$
$\frac{2}{5}+\frac{5}{9}+\frac{3}{5}+\frac{5}{9}$
$\frac{1}{3}+\frac{3}{8}+\frac{1}{4}$

2.$1\frac{7}{10}$ $\frac{3}{7}$ $\frac{7}{16}$ $\frac{1}{4}$ $2\frac{1}{9}$ $\frac{23}{24}$

3.解方程。（每题3★）
$x+\frac{4}{5}=\frac{13}{15}$
$x-\frac{1}{14}=\frac{5}{21}$
$\frac{12}{13}-x=\frac{1}{6}$

3.$x=\frac{1}{15}$ $x=\frac{13}{42}$ $x=\frac{59}{78}$