3.25×0.45+6.75×0.4531.5-24.5÷3.57.5×1026.3+3.7×2.8.
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解:①3.25×0.45+6.75×0.45,
=0.45×(3.25+6.75),
=0.45×10,
=4.5;
②31.5-24.5÷3.5,
=31.5-7,
=24.5;
③7.5×102,
=7.5×(100+2),
=7.5×100+7.5×2,
=750+15,
=765;
④6.3+3.7×2.8,
=6.3+10.36,
=16.66.
解析分析:①3.25×0.45+6.75×0.45利用乘法的分配律计算简便;
②按四则运算的顺序,先做24.5÷3.5,在算减;
③把102拆成100+2,然后利用乘法的分配律计算简便;
④按四则运算的顺序,先做3.7×2.8,再算加.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.