一、口算。
$37 + 59 =$ $51 ÷ 3 =$ $35 × 2 =$
$60 ÷ 5 =$ $71 × 7 =$ $55 × 3 =$
$240 ÷ 4 =$ $300 - 95 =$ $404 ÷ 4 =$
$480 - 370 =$ $930 ÷ 3 =$ $245 + 55 =$
$280 × 2 =$ $4 × 600 =$ $5 × 150 =$
$0 ÷ 189 =$ $884 - 84 =$ $366 ÷ 6 =$
$156 + 28 =$ $662 ÷ 2 =$ $204 ÷ 2 =$
$102 × 6 =$ $311 × 2 =$ $720 ÷ 4 =$

一、96 17 70
12 497 165
60 205 101
110 310 300
560 2400 750
0 800 61
184 331 102
612 622 180

二、计算下面各题。
$32 × (3 × 3)$ $478 - (231 + 23)$ $(138 + 286) ÷ 4$
$420 + 57 ÷ 3$ $686 ÷ (49 ÷ 7)$ $81 × (703 - 699)$

二、288 224 106
439 98 324