题目内容
| 用简便方法计算. 3.8×102 | 1.29+3.7+0.71+6.3 | 32×125 | 48+48×99. |
(1)3.8×102
=3.8×(100+2),
=3.8×100+3.8×2,
=380+7.6,
=387.6;
(2)1.29+3.7+0.71+6.3
=(1.29+0.71)+(3.7+6.3),
=2+10,
=12;
(3)32×125
=4×(8×125),
=4×1000,
=4000;
(4)48+48×99
=(99+1)×48,
=100×48,
=4800.
=3.8×(100+2),
=3.8×100+3.8×2,
=380+7.6,
=387.6;
(2)1.29+3.7+0.71+6.3
=(1.29+0.71)+(3.7+6.3),
=2+10,
=12;
(3)32×125
=4×(8×125),
=4×1000,
=4000;
(4)48+48×99
=(99+1)×48,
=100×48,
=4800.
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