(1)375+450÷18×25 (2)4.38×5.6+56.2×0.56(3)--+ (4)÷(-×)
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解:(1)375+450÷18×25,
=375+25×25,
=375+625,
=1000.
(2)4.38×5.6+56.2×0.56,
=4.38×5.6+5.62×5.6,
=(4.38+5.62)×5.6,
=10×5.6,
=56;
(3)--+,
=(+)-(+),
=2-1,
=1;
(4)÷(-×),
=÷(-),
=÷,
=.
解析分析:(1)先算除法,再算乘法,最后算加法;
(2)先根据积不变规律把56.2×0.56变成5.62×5.6,再运用乘法分配律简算;
(3)运用加法结合律以及减法的性质简算;
(4)先算小括号里面的乘法,再算小括号里面的减法,最后算括号外的除法.
点评:此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.