一、口算。
$65 + 35 =$ $0 ÷ 15 =$ $84 ÷ 6 =$
$27 × 3 =$ $76 ÷ 4 =$ $54 - 28 =$
$7 × 75 =$ $70 × 60 =$ $540 ÷ 9 =$
$153 ÷ 3 =$ $210 - 70 =$ $250 × 5 =$
$105 × 6 =$ $240 ÷ 5 =$ $145 + 55 =$
$707 ÷ 7 =$ $14 × 50 =$ $148 × 2 =$
$18 × 40 =$ $639 ÷ 9 =$ $43 × 30 =$
$20 × 72 =$ $63 × 50 =$ $810 ÷ 3 =$

一、100 0 14
81 19 26
525 4200 60
51 140 1250
630 48 200
101 700 296
720 71 1290
1440 3150 270

二、计算下面各题。
$12 × 36 - 170$         $304 ÷ 4 × 45$         $702 ÷ (404 - 398)$
$31 × (24 + 17)$         $512 - 524 ÷ 4$         $(450 - 394) × 22$

二、262 3420 117
1271 381 1232