一、口算。
323 + 117 = 822 + 18 = 810 ÷ 9 =
220 × 6 = 92 - 17 = 320 ÷ 16 =
105 × 6 = 300 ÷ 4 = 367 + 63 =
200 ÷ 4 = 124 - 48 = 35 × 60 =
7200 ÷ 80 = 42 × 30 = 85 + 38 =
30 × 41 = 450 ÷ 90 = 260 ÷ 13 =
437 - 35 = 102 × 6 = 59 + 13 =
60 × 31 = 65 - 29 = 762 ÷ 3 =

440 840 90 1320 75 20 630 75 430 50 76 2100 90 1260 123 1230 5 20 402 612 72 1860 36 254

323 + 117 = 440
822 + 18 = 840
810 ÷ 9 = 90
220 × 6 = 1320
92 - 17 = 75
320 ÷ 16 = 20
105 × 6 = 630
300 ÷ 4 = 75
367 + 63 = 430
200 ÷ 4 = 50
124 - 48 = 76
35 × 60 = 2100
7200 ÷ 80 = 90
42 × 30 = 1260
85 + 38 = 123
30 × 41 = 1230
450 ÷ 90 = 5
260 ÷ 13 = 20
437 - 35 = 402
102 × 6 = 612
59 + 13 = 72
60 × 31 = 1860
65 - 29 = 36
762 ÷ 3 = 254

二、计算下面各题,怎样简便就怎样计算。
500 - 391 ÷ 17 × 14 89 × 11 + 11 + 90 700 - 137 - 263 + 300
389 + 180 ÷ 5 × 20 (714 - 12) ÷ 27 - 19 (420 - 100 ÷ 10) × 11

178 1080 600 1109 7 4510

500 - 391 ÷ 17 × 14
= 500 - 23 × 14
= 500 - 322
= 178
89 × 11 + 11 + 90
= (89 + 1) × 11 + 90
= 90 × 11 + 90
= 990 + 90
= 1080
700 - 137 - 263 + 300
= (700 + 300) - (137 + 263)
= 1000 - 400
= 600
389 + 180 ÷ 5 × 20
= 389 + 36 × 20
= 389 + 720
= 1109
(714 - 12) ÷ 27 - 19
= 702 ÷ 27 - 19
= 26 - 19
= 7
(420 - 100 ÷ 10) × 11
= (420 - 10) × 11
= 410 × 11
= 4510