一、直接写出得数。(共 32 分)
720 - 450 = 17 × 20 = 76 - 49 = (47 + 13) × 3 =
48 + 29 = 290 + 170 = 81 ÷ 3 = 38 - 12 × 3 =
78 × 20 = 105 × 6 = 120 × 7 = 270 ÷ (47 - 44) =
112 × 3 = 180 ÷ 4 = 880 ÷ 8 = 80 + 120 - 77 =
303 × 5 = 600 ÷ 5 = 156 + 844 = 80 + 80 × 80 =
217 ÷ 7 = 212 × 4 = 910 × 8 = (50 + 88) ÷ 2 =
981 ÷ 9 = 220 × 5 = 25 × 30 = 30 × 2 - 22 =
41 × 41 ≈ 18 × 42 ≈ 89 × 49 ≈ 86 × 10 + 60 =

270 340 27 180
77 460 27 2
1560 630 840 90
336 45 110 123
1515 120 1000 6480
31 848 7280 69
109 1100 750 38
1600 800 4500 920

二、用竖式计算,带☆的要验算。(共 20 分)
17 × 23 = ☆923 - 67 = 653 + 378 =
25 × 16 = 47 × 36 = ☆29 × 55 =

391 856 1031
400 1692 1595
竖式及验算略

三、计算下面各题。(共 18 分)
780 ÷ (71 - 65) 488 + 72 × 15 (49 + 21) × 57
823 - (146 + 119) 276 + 328 ÷ 8 279 ÷ 9 × 36

130 1568 3990
558 317 1116