一、口算。
93×3 =
92 + 68 =
82 - 37 =
700×5 =
420÷4 =
950÷5 =
24×40 =
28 + 16 =
70×21 =
77÷7 =
41×30 =
810÷3 =
600 - 70 =
700÷2 =
50×60 =
$\frac{1}{4}+\frac{1}{4}=$
$\frac{17}{30}-\frac{8}{30}=$
$\frac{2}{10}+\frac{7}{10}=$
$\frac{8}{9}-\frac{6}{9}=$
$\frac{5}{16}+\frac{9}{16}=$
$\frac{7}{13}-\frac{4}{13}=$
$\frac{1}{8}+\frac{5}{8}=$
$\frac{4}{5}-\frac{2}{5}=$
$\frac{6}{7}-\frac{6}{7}=$
$\frac{3}{15}+\frac{1}{15}=$
$\frac{25}{36}-\frac{11}{36}=$
$\frac{3}{11}+\frac{2}{11}=$
$\frac{9}{10}-\frac{2}{10}=$
$\frac{7}{25}+\frac{11}{25}=$
$\frac{6}{13}-\frac{3}{13}=$

279 160 45
3500 105 190
960 44 1470
11 1230 270
530 350 3000
$\frac{2}{4}$ $\frac{9}{30}$ $\frac{9}{10}$
$\frac{2}{9}$ $\frac{14}{16}$ $\frac{3}{13}$
$\frac{6}{8}$ $\frac{2}{5}$ 0
$\frac{4}{15}$ $\frac{14}{36}$ $\frac{5}{11}$
$\frac{7}{10}$ $\frac{18}{25}$ $\frac{3}{13}$