《2025年灵机一动小学数学口算心算三年级上册苏教版》

口算练习 31
1
5×897≈4500
3×302≈900
403×9≈3600
68×7≈490
61×5≈300
4×312=1248
354×0=0
230×6+6=1386
7×430+8=3018
412×3=1236
4×540=2160
760×5=3800
8×210=1680
410×9=3690
2
56÷8+7=14
36÷9+4=8
390-120=270
328+272=600
7200-400=6800
280-80=200
75×3+10=235
56÷7+8=16
360×4=1440
9900-900=9000
6×440=2640
3×600+60=1860
310×3=930
603×6+42=3660
3
5000-600=4400
72÷8×2=18
81÷9×3=27
4×720=2880
375+45=420
176+24=200
32÷8×9=36
42×4=168
9×120=1080
320×8=2560
810×6=4860
9×705=6345
607×3=1821
220×6=1320
注：标“≈”题请写出估算得数。

答案： 解析：本题主要考查了乘法、除法、加法和减法的口算能力，包括估算和精确计算。
答案：
$5 × 897 \approx 4500$
$3 × 302 \approx 900$
$403 × 9 \approx 3600$
$68 × 7 \approx 490$
$61 × 5 \approx 300$
$4 × 312 = 1248$
$354 × 0 = 0$
$230 × 6 + 6 = 1386$
$7 × 430 + 8 = 3018$
$412 × 3 = 1236$
$4 × 540 = 2160$
$760 × 5 = 3800$
$8 × 210 = 1680$
$410 × 9 = 3690$
$56 ÷ 8 + 7 = 14$
$36 ÷ 9 + 4 = 8$
$390 - 120 = 270$
$328 + 272 = 600$
$7200 - 400 = 6800$
$280 - 80 = 200$
$75 × 3 + 10 = 235$
$56 ÷ 7 + 8 = 16$
$360 × 4 = 1440$
$9900 - 900 = 9000$
$6 × 440 = 2640$
$3 × 600 + 60 = 1860$
$310 × 3 = 930$
$603 × 6 + 42 = 3660$
$5000 - 600 = 4400$
$72 ÷ 8 × 2 = 18$
$81 ÷ 9 × 3 = 27$
$4 × 720 = 2880$
$375 + 45 = 420$
$176 + 24 = 200$
$32 ÷ 8 × 9 = 36$
$42 × 4 = 168$
$9 × 120 = 1080$
$320 × 8 = 2560$
$810 × 6 = 4860$
$9 × 705 = 6345$
$607 × 3 = 1821$
$220 × 6 = 1320$