一、口算。
$24 + 73 =$ $0 ÷ 56 =$ $90 - 80 ÷ 5 =$
$12 × 6 =$ $90 ÷ 6 =$ $101 × 3 × 3 =$
$200 ÷ 4 =$ $2 × 203 =$ $450 ÷ 9 + 76 =$
$230 × 5 =$ $620 - 240 =$ $900 ÷ 3 ÷ 6 =$
$690 + 70 =$ $880 ÷ 2 =$ $3 × 200 + 40 =$
$110 × 7 =$ $254 - 72 =$ $560 ÷ (4 × 2) =$
$210 ÷ 5 =$ $0 + 226 =$ $0 ÷ (150 + 170) =$
$233 × 4 =$ $386 ÷ 2 =$ $125 × (64 ÷ 8) =$

一、97 0 74
72 15 909
50 406 126
1150 380 50
760 440 640
770 182 70
42 226 0
932 193 1000

二、用竖式计算，带*的要验算。
$450 × 7$         $145 ÷ 5$   *$934 ÷ 7$
$762 ÷ 3$         $385 × 4$   *$624 ÷ 3$

二、3150 29
133……3
254 1540
208