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(zhuān)題:運(yùn)算順序及法則,運(yùn)算定律及簡(jiǎn)算
分析:(1)按照從左向右的順序進(jìn)行計(jì)算;
(2)按照從左向右的順序進(jìn)行計(jì)算;
(3)先算加法,再算減法;
(4)根據(jù)加法交換律和結(jié)合律進(jìn)行簡(jiǎn)算;
(5)根據(jù)加法交換律和結(jié)合律進(jìn)行簡(jiǎn)算;
(6)根據(jù)加法交換律和結(jié)合律進(jìn)行簡(jiǎn)算.
解答:
解:(1)
+
-
=
-
=
;
(2)
+
-
=
-
=
;
(3)
-(
+
)
=
-
=
;
(4)
+1.7+8.3+
=(
+
)+(1.7+8.3)
=1+10
=11;
(5)
+
+
+
=(
+
)+(
+
)
=2+
=2
;
(6)
+
+
+
=(
+
)+(
+
)
=
+1
=1
.
點(diǎn)評(píng):考查了運(yùn)算定律與簡(jiǎn)便運(yùn)算,四則混合運(yùn)算.注意運(yùn)算順序和運(yùn)算法則,靈活運(yùn)用所學(xué)的運(yùn)算定律簡(jiǎn)便計(jì)算.