题目内容
用简便方法计算
1.2×2.5+2.8×2.5 | 4.8×2.5. |
分析:(1)根据乘法分配律进行简算;
(2)把4.8拆成4×1.2,再根据乘法交换律和结合律进行简算.
(2)把4.8拆成4×1.2,再根据乘法交换律和结合律进行简算.
解答:解:
(1)1.2×2.5+2.8×2.5,
=(1.2+2.8)×2.5,
=4×2.5,
=10;
(2)4.8×2.5,
=(4×1.2)×2.5,
=(4×2.5)×1.2,
=10×1.2,
=12.
(1)1.2×2.5+2.8×2.5,
=(1.2+2.8)×2.5,
=4×2.5,
=10;
(2)4.8×2.5,
=(4×1.2)×2.5,
=(4×2.5)×1.2,
=10×1.2,
=12.
点评:根据题意,找准所运用的运算定律,然后再进一步计算即可.
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