一、口算。
$86 + 98 =$ $32×8 =$ $78÷6 =$
$94÷2 =$ $43×3 =$ $75×7 =$
$7×200 =$ $950 - 250 =$ $217÷7 =$
$180×5 =$ $14×50 =$ $12×80 =$
$420÷3 =$ $62×20 =$ $106÷2 =$
$404×9 =$ $345÷3 =$ $54×30 =$
$\dfrac{7}{8} - \dfrac{2}{8} =$ $\dfrac{6}{7} - \dfrac{1}{7} =$ $\dfrac{5}{6} - \dfrac{2}{6} =$
$\dfrac{7}{9} + \dfrac{1}{9} =$ $\dfrac{2}{5} + \dfrac{2}{5} =$ $\dfrac{6}{7} - \dfrac{3}{7} =$
$\dfrac{5}{9} + \dfrac{1}{9} =$ $\dfrac{5}{9} - \dfrac{4}{9} =$ $\dfrac{3}{8} + \dfrac{4}{8} =$
$\dfrac{1}{5} + \dfrac{2}{5} =$ $\dfrac{3}{4} - \dfrac{2}{4} =$ $\dfrac{2}{9} + \dfrac{4}{9} =$

184 256 13
47 129 525
1400 700 31
900 700 960
140 1240 53
3636 115 1620
$\frac{5}{8} \frac{5}{7} \frac{3}{6}$
$\frac{8}{9} \frac{4}{5} \frac{3}{7}$
$\frac{6}{9} \frac{1}{9} \frac{7}{8}$
$\frac{3}{5} \frac{1}{4} \frac{6}{9}$

二、先涂色表示结果，再列式计算。
1. $\dfrac{(\mathrm{\_\_\_\_\_\_})}{(\mathrm{\_\_\_\_\_\_})} + \dfrac{(\mathrm{\_\_\_\_\_\_})}{(\mathrm{\_\_\_\_\_\_})} = \dfrac{(\mathrm{\_\_\_\_\_\_})}{(\mathrm{\_\_\_\_\_\_})}$
2. $\dfrac{(\mathrm{\_\_\_\_\_\_})}{(\mathrm{\_\_\_\_\_\_})} - \dfrac{(\mathrm{\_\_\_\_\_\_})}{(\mathrm{\_\_\_\_\_\_})} = \dfrac{(\mathrm{\_\_\_\_\_\_})}{(\mathrm{\_\_\_\_\_\_})}$

涂色略
$1. \frac{1}{5} + \frac{3}{5} = \frac{4}{5}$
2. $\frac{7}{8}-\frac{5}{8}=\frac{2}{8}$