一、口算。
39 + 39 =
51 ÷ 3 =
9 × 15 =
90 × 5 =
42 - 19 =
24 × 8 =
180 ÷ 6 =
2 × 320 =
800 - 46 =
101 × 9 =
550 ÷ 5 =
36 × 20 =
70 × 11 =
132 × 3 =
148 ÷ 2 =
620 + 38 =
816 ÷ 2 =
53 × 20 =
50 × 80 =
19 × 40 =
117 ÷ 3 =
126 × 3 =
680 ÷ 4 =
20 × 47 =

一、78 17 135
450 23 192
30 640 754
909 110 720
770 396 74
658 408 1060
4000 760 39
378 170 940

二、计算下面各题。
467 - (167 - 88)
420 ÷ 7 × 49
(34 + 26) × 78
16 × (312 - 272)
260 - 180 ÷ 4
(200 - 144) ÷ 4

二、388 2940 4680
640 215 14