考點(diǎn):分?jǐn)?shù)的四則混合運(yùn)算,運(yùn)算定律與簡(jiǎn)便運(yùn)算
專題:運(yùn)算順序及法則,運(yùn)算定律及簡(jiǎn)算
分析:(1)先算除法,再算乘法,最后算加法;
(2)把除法化成乘法,再運(yùn)用乘法的分配律進(jìn)行簡(jiǎn)算;
(3)先算小括號(hào)里的除法,再算去括號(hào)進(jìn)行計(jì)算;
(4)運(yùn)用乘法的分配律進(jìn)行簡(jiǎn)算;
(5)運(yùn)用乘法的分配律進(jìn)行簡(jiǎn)算;
(6)把除法化成乘法,再運(yùn)用乘法的分配律進(jìn)行簡(jiǎn)算.
解答:
解:(1)
÷
×
+
=
×
+
=
+
=
;
(2)
×
-
÷
=
×
-
×
=(
-
)×
=1×
=
;
(3)
-(
÷
+
)
=
-(
+
)
=
-
-
=1-
=
;
(4)30×(
+
)
=30×
+30×
=6+10
=16;
(5)
×
+
×
=
×(
+
)
=
×1
=
;
(6)
×
+
÷9
=
×
+
×
=(
+
)×
=1×
=
.
點(diǎn)評(píng):此題考查分?jǐn)?shù)四則混合運(yùn)算的順序,并且能夠靈活運(yùn)用這些運(yùn)算性質(zhì)和運(yùn)算定律進(jìn)行簡(jiǎn)便計(jì)算.