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)根據(jù)乘法結(jié)合律進(jìn)行簡(jiǎn)算;
(2)先算小括號(hào)里面的減法,再算除法,最后算括號(hào)外面的減法;
(3)根據(jù)乘法分配律進(jìn)行簡(jiǎn)算;
(4)先算加法,再算減法,最后算除法;
(5)先算除法,再算加法,最后算減法;
(6)根據(jù)乘法分配律進(jìn)行簡(jiǎn)算.
解答:
解:(1)12.5×32
=12.5×(8×4)
=(12.5×8)×4
=100×4
=400;
(2)18-10.4÷(6.2-4.9)
=18-10.4÷1.3
=18-8
=10;
(3)(1-
+
)×36
=1×36-
×36+
×36
=36-24+10
=12+10
=22;
(4)[1-(
+
)]÷
=[1-
]÷
=
÷
=
;
(5)5-(
÷
+
)
=5-(4+
)
=5-4
=
;
(6)
×22-
×6
=
×22-
×3
=
×(22-3)
=
×19
=6.
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.