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

1.$\frac{3}{5}$
2.$\frac{2}{7}$
3.$\frac{2}{3}$
4.$\frac{1}{6}$
5.$\frac{1}{6}$
6.$\frac{5}{6}$
7.$\frac{2}{5}$
8.$\frac{7}{9}$
9.$\frac{1}{2}$
10.$5\frac{1}{3}$
11.$1$
12.$\frac{9}{8}$
13.$\frac{7}{12}$
14.$\frac{1}{3}$
15.$\frac{1}{12}$
16.$\frac{17}{72}$
17.$\frac{11}{9}$
18.$\frac{29}{30}$
19.$\frac{9}{11}$
20.$\frac{5}{9}$

2.计算下面各题,能简算的要简算。(每题 3 ★)
$\frac{3}{5}+\frac{7}{10}+\frac{2}{5}$
$\frac{7}{8}-(\frac{3}{8}+\frac{2}{5})$
$1-\frac{15}{19}-\frac{4}{19}$
$\frac{7}{9}-(\frac{4}{7}-\frac{2}{9})$
$\frac{2}{9}+\frac{4}{5}+\frac{7}{9}+\frac{1}{5}$
$\frac{5}{14}-(\frac{2}{7}-\frac{1}{5})$
$\frac{5}{6}-\frac{1}{4}+\frac{2}{3}$
$3-\frac{7}{13}-\frac{6}{13}$
$\frac{6}{11}+\frac{11}{15}+\frac{5}{11}-\frac{2}{5}$

1.$1\frac{7}{10}$
2.$\frac{1}{10}$
3.$0$
4.$\frac{3}{7}$
5.$2$
6.$\frac{19}{70}$
7.$\frac{5}{4}$
8.$2$
9.$1\frac{1}{3}$