考點(diǎn):小數(shù)四則混合運(yùn)算,運(yùn)算定律與簡(jiǎn)便運(yùn)算,分?jǐn)?shù)的四則混合運(yùn)算
專題:運(yùn)算順序及法則,運(yùn)算定律及簡(jiǎn)算
分析:(1)先算乘除后算減法;
(2)先算9.43減去2.43,再算加法;
(3)先算小括號(hào)內(nèi)的,再算乘法,最后算加法;
(4)從左往右做乘法;
(5)運(yùn)用乘法分配律的逆運(yùn)算解答;
(6)先算小括號(hào)內(nèi)的再算中括號(hào)內(nèi)的,最后算括號(hào)外面的.
解答:
解:(1)624-3.2×1.5÷0.1
=624-4.8÷0.1
=624-48
=576
(2)9.43+0.78-2.43
=9.43-2.43+0.78
=7+0.78
=7.78
(3)
+(
+
)×
=
+×
=
+=1
(4)
×15×
=9×
=2
(5)
×5+
÷
=(
+)×5
=1×5
=5
(6)
-[(
+
)÷
]
=
-[
×
]
=
-=
點(diǎn)評(píng):此題是考查四則混合運(yùn)算,要仔細(xì)觀察算式的特點(diǎn),靈活運(yùn)用一些定律進(jìn)行簡(jiǎn)便計(jì)算.