考点:小数四则混合运算
专题:运算顺序及法则
分析:(1)首先计算小括号里面的,然后计算中括号里面的,最后计算中括号外面的即可;
(2)(6)根据乘法分配律简算即可;
(3)根据乘法交换律和结合律简算即可;
(4)根据除法的性质简算即可;
(5)根据减法的性质简算即可.
解答:
解:(1)0.6×[(5-0.68)÷1.2]
=0.6×[4.32÷1.2]
=0.6×3.6
=2.16
(2)4.3×10.2
=4.3×(10+0.2)
=4.3×10+4.3×0.2
=43+0.86
=43.86
(3)1.25×19.4×0.8
=1.25×0.8×19.4
=1×19.4
=19.4
(4)38.2÷0.25÷4
=38.2÷(0.25×4)
=38.2÷1
=38.2
(5)17.6-0.5×0.5-0.75
=17.6-0.25-0.75
=17.6-(0.25+0.75)
=17.6-1
=16.6
(6)0.8×(12.5+1.25)
=0.8×12.5+0.8×1.25
=10+1
=11
点评:此题主要考查了小数四则混合运算,注意运算顺序,注意乘法运算定律、减法、除法的性质的应用.