×(-)=(13+)×=×12+=×+÷=×(-×)=×11-=×+×=+++=××=101×-=×48=×34×7×=
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解:(1)×(-),
=×,
=;
(2)(13+)×,
=13×+×,
=9+,
=9;
(3)×12+,
=×(12+1),
=×13,
=66;
(4)×+÷,
=×+×,
=(+)×,
=2×,
=;
(5)×(-×),
=×(-),
=×,
=;
(6)×11-,
=×(11-1),
=×10,
=9;
(7)×+×,
=×(+),
=×1,
=;
(8)+++,
=(+)+(+),
=1+,
=1;
(9)××,
=×,
=;
(10)101×-,
=(101-1)×,
=100×,
=;
(11)×48,
=×(47+1),
=×47+×1,
=6+,
=6;
(12)×34×7×,
=(×7)×(×34),
=1×4,
=4.
解析分析:(1)(9)先算小括号里面的减法,再算括号外的乘法;
(2)(3)(6)(7)(10)运用乘法分配律简算;
(4)先把除法变成乘法,再运用乘法分配律简算;
(5)先算小括号里面的乘法,再算小括号里面的加减法,最后算括号外的乘法;
(8)运用加法交换律和结合律简算;
(11)先把48分解成47+1,再运用乘法分配律简算;
(12)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.