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(1)13.72-1.65-2.35
(2)2.4+3.6÷1.2×0.2
(3)(12.5+1.25)×0.8      
(4)5.4×7.2+2.8×5.4
(5)2÷(1.2-0.4×2.5)
(6)0.3×[(13.4-10)÷0.5+1.5].

解:(1)13.72-1.65-2.35,
=13.72-(1.65+2.35),
=13.72-4,
=9.72;
(2)2.4+3.6÷1.2×0.2,
=2.4+3×0.2
=2.4+0.6,
=3;
(3)(12.5+1.25)×0.8,
=12.5×0.8+1.25×0.8,
=10+1,
=11;
(4)5.4×7.2+2.8×5.4
=(7.2+2.8)×5.4,
=10×5.4,
=54;
(5)2÷(1.2-0.4×2.5)
=2÷(1.2-1),
=2÷0.2,
=10;
(6)0.3×[(13.4-10)÷0.5+1.5]
=0.3×[3.4÷0.5+1.5],
=0.3×[6.8+1.5],
=0.3×8.3,
=2.49.
分析:算式(1)可据一个数减两个数等于减去这两个数的和的减法性质进行计算;(3)(4)可据乘法分配律进行简便计算;其余算式据四则混合运算法则计算即可.
点评:完成有关于小数的四则混合运算时要注意小数点位置的变化.
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