用你喜欢的方法计算. 15-4.25-525×32×125[4-(-)]×8÷+5.2×709×99+7092.5××0.4×2.
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解:(1)15-4.25-5,
=15-(4.25+5),
=15-10,
=5;
(2)25×32×125,
=25×4×8×125,
=(25×4)×(8×125),
=100×1000,
=100000;
(3)[4-(-)]×,
=[4-]×,
=×,
=;
(4)8÷+5.2×,
=8×+5.2×,
=3+1.95,
=4.95;
(5)709×99+709,
=709×(99+1),
=709×100,
=70900;
(6)2.5××0.4×2,
=(2.5×0.4)×(×2),
=1×1,
=1.
解析分析:(1)根据加减法的性质简算;
(2)先把32分解成8×4,再运用乘法结合律简算;
(3)先算小括号里面的减法,再算中括号里面的减法,最后算括号外的乘法;
(4)同时运算除法和乘法,再算加法;
(5)运用乘法分配律简算;
(6)运用乘法交换律和结合律简算.
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.