考點(diǎn):整數(shù)、分?jǐn)?shù)、小數(shù)、百分?jǐn)?shù)四則混合運(yùn)算
專(zhuān)題:運(yùn)算順序及法則
分析:(1)根據(jù)乘法分配律進(jìn)行簡(jiǎn)算;
(2)根據(jù)乘法分配律進(jìn)行簡(jiǎn)算;
(3)根據(jù)乘法分配律進(jìn)行簡(jiǎn)算;
(4)根據(jù)乘法分配律進(jìn)行簡(jiǎn)算;
(5)先算加法,再算減法,最后算乘法.
解答:
解:(1)(
+
)×8
=
×8+
×8
=
+3
=5
;
(2)5.46×101-5.46
=5.46×(101-1)
=5.46×100
=546;
(3)111×5+9÷
=111×5+9×5
=(111+9)×5
=120×5
=600;
(4)0.72×6.7+7.2×33%
=7.2×0.67+7.2×33%
=7.2×(0.67+33%)
=7.2×1
=7.2;
(5)180×[
-(
+
)]
=180×[
-
]
=180×
=45.
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.