1. 直接写出得数。
100 - 51 = 560 + 290 = 160 ÷ 4 = 25 × 2 + 20 =
54 × 20 = 108 × 7 = 560 ÷ 4 = 32 + 64 ÷ 8 =
48 × 3 = 5 × 45 = 60 × 60 = 120 ÷ 8 × 0 =
59 × 30 = 50 × 45 = 140 ÷ 5 = 27 × 10 + 10 =
602 × 4 = 12 × 30 = 43 × 60 = 54 × 5 ÷ 6 =
72 ÷ 4 = 404 × 8 = 66 × 5 = 6 × (31 - 11) =
90 ÷ 5 = 360 ÷ 2 = 204 ÷ 4 = (24 + 66) ÷ 3 =
420 ÷ 4 = 55 × 40 = 92 × 40 = 210 - 63 - 37 =

1. 49 850 40 70
1080 756 140 40
144 225 3600 0
1770 2250 28 280
2408 360 2580 45
18 3232 330 120
18 180 51 30
105 2200 3680 110

2. 计算下面各题。
548 - (348 - 200) (973 - 892) × 90 (271 - 187) × 72

2. 400 7290 6048