问题标题:
用简便方法计算1.2×2.5+2.8×2.54.8×2.5.
问题描述:
用简便方法计算
1.2×2.5+2.8×2.5 | 4.8×2.5. |
苏占东回答:
(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.
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