考點(diǎn):分?jǐn)?shù)的四則混合運(yùn)算
專(zhuān)題:運(yùn)算順序及法則
分析:(1)運(yùn)用加法的交換律、減法的性質(zhì)進(jìn)行簡(jiǎn)算;
(2)先算減法,再算加法;
(3)從左向右進(jìn)行計(jì)算即可;
(4)從左向右進(jìn)行計(jì)算即可;
(5)運(yùn)用加法的交換律、結(jié)合律進(jìn)行簡(jiǎn)算;
(6)運(yùn)用減法的性質(zhì)進(jìn)行簡(jiǎn)算;
(7)先算小括號(hào)里的減法,再算括號(hào)外的減法.
解答:
解:(1)
-
+
-
=(
+
)-(
+
)
=1-1
=0;
(2)
+
-
=
-
+
=0
+=
;
(3)
+
-
=
-
=
;
(4)
-
+
=
+
=
;
(5)
+
+
+
=
+
+
+
=(
+
)+(
+
)
=
+=
;
(6)8-
-
=8-(
+
)
=8-1
=7;
(7)
-(
-
)
=
-
=
.
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.