①11.83-7.85-0.15
②25×125×32
③12×(
-
)④
×0.4+
×
+0.4×
.解:①11.83-7.85-0.15,=11.83-(7.85+0.15),
=11.83-8,
=3.83;
②25×125×32,
=25×125×4×8,
=(25×4)×(125×8),
=100×1000,
=100000;
③12×(
-
),=12×
-
×12,=8-2,
=6;
④
×0.4+
×
+0.4×
,=
×0.4+
×0.4+0.4×
,=(
+
+
)×0.4,=1×0.4,
=0.4.
分析:①运用减法的性质简算;
②把32看作4×8,运用乘法交换律与结合律简算;
③运用乘法分配律简算;
④把
化为小数0.4,运用乘法分配律简算.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定律进行简便计算.