计算下面各题,能简算的要简算.
(1)975-384÷16×25 (2)÷(+)+1.65(3)5.25+3-1.8+2(4)×1.5-1.5×(5)12.5×0.25×32 (6)36×(+)÷2%
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解:(1)975-384÷16×25
=975-24×25,
=975-600,
=375;
(2)÷(+)+1.65
=÷(+)+1.65,
-×+1.65,
=+1.65,
=0.25+1.65,
=1.9;
(3)5.25+3-1.8+2
=5.25+3.8-1.8+2.75,
=5.25+2.75+(3.8-1.8),
=8+2,
=10;
(4)×1.5-1.5×
=(-)×1.5,
=3×1.5,
=4.5;
(5)12.5×0.25×32
=12.5×0.25×8×4,
=(12.5×8)×(0.25×4),
=100×1,
=100;
(6)36×(+)÷2%
=[36×+36×]÷2%,
=[10+8]÷2%,
=18÷2%,
=900.
解析分析:算式(1)(2)根据四则混合运算的运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的;
算式(3)可将式中分数化为小数后,根据加法交换律及结合律进行计算;
算式(4)(6)可根据乘法分配律进行计算;
算式(5)可将式中32拆分为8×4后再根据乘法结合律计算.
点评:完成本题要细心分析式中数据的特点及内在联系,然后选用合适的方法进行计算.