一、口算。
50 - 16 =
160÷2 =
65 + 28 =
6×600 =
85×2 =
32×40 =
99÷9 =
840÷4 =
560÷8 =
18×50 =
25×60 =
200 - 57 =
52 + 38 =
630÷3 =
6×130 =
$\frac{1}{5}+\frac{3}{5}=$
$\frac{7}{8}-\frac{3}{8}=$
$\frac{1}{4}+\frac{2}{4}=$
$\frac{5}{11}-\frac{2}{11}=$
$\frac{6}{13}+\frac{1}{13}=$
$\frac{1}{7}+\frac{4}{7}=$
$\frac{2}{6}+\frac{3}{6}=$
$\frac{7}{8}-\frac{7}{8}=$
$\frac{9}{10}-\frac{7}{10}=$
$\frac{7}{9}+\frac{1}{9}=$
$\frac{5}{12}+\frac{1}{12}=$
$\frac{9}{14}-\frac{5}{14}=$
$\frac{15}{17}-\frac{9}{17}=$
$\frac{13}{18}-\frac{5}{18}=$
$\frac{3}{13}+\frac{4}{13}=$

34 80 93
3600 170 1280
11 210 70
900 1500 143
90 210 780
$\frac{4}{5}$ $\frac{4}{8}$ $\frac{3}{4}$
$\frac{3}{11}$ $\frac{7}{13}$ $\frac{5}{7}$
$\frac{5}{6}$ 0 $\frac{2}{10}$
$\frac{8}{9}$ $\frac{6}{12}$ $\frac{4}{14}$
$\frac{6}{17}$ $\frac{8}{18}$ $\frac{7}{13}$

二、计算下面各题。
540 - 497÷7
(40 + 60)÷4
(100 - 69)×36

469 25 1116