(1)18
-(2.35+8.6)(2)68÷[0.5×(7.5-0.7)]
(3)352-162÷36×24
(4)[
-(
-
)]×
(5)(
+
+
)÷
(6)
×[
÷(
×
)].解:(1)18
-(2.35+8.6),=18.6-2.35-8.6,
=18.6-8.6-2.35,
=10-2.35,
=7.65;
(2)68÷[0.5×(7.5-0.7)],
=68÷[0.5×6.8],
=68÷3.4,
=20;
(3)352-162÷36×24,
=352-4.5×24,
=352-108,
=244;
(4)[
-(
-
)]×
,=[
-
]×
,=
×
,=
;(5)(
+
+
)÷
,=(
+
+
)×36,=
×36+
×36+
×36,=12+6+4,
=22;
(6)
×[
÷(
×
)],=
×[
÷
],=
×
,=
.分析:(1)根据连减的性质进行简算;
(2)先算减法,再算乘法,最后算除法;
(3)先算除法,再算乘法,最后算减法;
(4)先算小括号里面的减法,再算中括号里面的减法,最后算乘法;
(5)根据乘法分配律进行简算;
(6)先算小括号里面的乘法,再算中括号里面的除法,最后算括号外面的乘法.
点评: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.