1. 直接写出得数。
$86 - 69 =$ $216 - 107 =$ $390 ÷ 6 =$ $258 + 232 - 140 =$
$28 × 30 =$ $220 ÷ 4 =$ $309 ÷ 3 =$ $26 × 3 × 3 =$
$4 × 130 =$ $240 ÷ 5 =$ $219 - 179 =$ $69 ÷ 3 × 20 =$
$71 × 30 =$ $116 + 78 =$ $4500 - 600 =$ $28 × 20 + 45 =$
$84 × 50 =$ $37 × 20 =$ $3800 + 900 =$ $36 × (30 ÷ 5) =$
$7 × 101 =$ $240 × 3 =$ $27 × 20 =$ $(220 - 20) ÷ 8 =$
$\frac{1}{9} + \frac{3}{9} =$ $\frac{2}{6} + \frac{1}{6} =$ $\frac{9}{10} - \frac{5}{10} =$ $\frac{5}{13} - \frac{2}{13} =$
$\frac{5}{8} - \frac{2}{8} =$ $\frac{6}{7} - \frac{2}{7} =$ $\frac{7}{8} - \frac{3}{8} =$ $\frac{3}{14} - \frac{1}{14} =$

1. 17 109 65 350 840 55 103 234 520 48 40 460 2130 194 3900 605 4200 740 4700 216 707 720 540 25 $\dfrac{4}{9}$ $\dfrac{3}{6}$ $\dfrac{4}{10}$ $\dfrac{3}{13}$ $\dfrac{3}{8}$ $\dfrac{4}{7}$ $\dfrac{4}{8}$ $\dfrac{2}{14}$

2. 计算下面各题。
$35 × 23 - 147$ $424 ÷ (24 ÷ 6)$ $38 × (86 - 68)$
$232 - 492 ÷ 6$ $41 × 56 + 103$ $268 ÷ 4 × 19$

2. 658 106 684 150 2399 1273

仔细观察例题，照样子巧算。
例：

$61 × 69 =$ $43 × 47 =$
$48 × 42 =$ $72 × 78 =$
$65 × 65 =$ $54 × 56 =$

思维提升
4209 2021 2016 5616 4225 3024