计算下面各题,能简算的要简算.
35+71+29+65125×5×8×243×23+57×23[250-(43+132)]×18900÷[3×(48-23)]99×76.
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解:(1)35+71+29+65,
=(35+65)+(71+29),
=100+100,
=200;
(2)125×5×8×2,
=(125×8)×(5×2),
=1000×10,
=10000;
(3)43×23+57×23,
=(43+57)×23,
=100×23,
=2300;
(4)[250-(43+132)]×18,
=[250-175]×18,
=75×18,
=1350;
(5)900÷[3×(48-23)],
=900÷(3×25),
=900÷75,
=12;
(6)99×76,
=(100-1)×76,
=100×76-1×76,
=7600-76,
=7524.
解析分析:(1)运用加法结合律简算;
(2)运用乘法结合律简算;
(3)运用乘法分配律简算;
(4)先算小括号里面的加法,再算中括号里面的减法,最后算括号外的乘法;
(5)先算小括号里面的减法,再算中括号里面的乘法,最后算括号外的除法;
(6)先把99分解成100-1,再运用乘法分配律简算.
点评:本题考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算律简便计算.