题目内容

0.79+0.79×99= 1÷5+1÷5= 0.89×101-0.89= 2-0.64-0.36=
1.1-2.7÷27= 12.4×11-12.4= 1.25×3.3×0= 20-3.7-7.3=
5×0.75÷1.5×0.75= 1-0.1×0.1= 6×0.125×8= 1×0.4÷1×0.4=
分析:(1)(3)(6)运用乘法分配律简算;(2)先算除法,再算加法;(4)(8)运用减法的性质简算;(5)先算除法,再算减法;(7)任何数与0相乘都得0;(9)先算除法,再算乘法;(10)先算乘法,再算减法;(11)运用乘法结合律简算;(12)从左往右依次计算.
解答:解:
(1)0.79+0.79×99=79;       (2)1÷5+1÷5=0.4;     (3)0.89×101-0.89=89; (4)2-0.64-0.36=1;

(5)1.1-2.7÷27=1;           (6)12.4×11-12.4=124; (7)1.25×3.3×0=0;    (8)20-3.7-7.3=9;

(9)5×0.75÷1.5×0.75=1.875;(10)1-0.1×0.1=0.99; (11)6×0.125×8=6;(12)1×0.4÷1×0.4=0.16.
点评:此题考查了四则混合运算,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.
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