考點(diǎn):分?jǐn)?shù)的四則混合運(yùn)算,整數(shù)四則混合運(yùn)算,運(yùn)算定律與簡便運(yùn)算,小數(shù)四則混合運(yùn)算
專題:運(yùn)算順序及法則,運(yùn)算定律及簡算
分析:(1)根據(jù)乘法分配律進(jìn)行簡算;
(2)根據(jù)乘法分配律進(jìn)行簡算;
(3)先算小括號里面的減法,再算中括號里面的減法,最后算除法;
(4)根據(jù)乘法分配律進(jìn)行簡算.
解答:
解:(1)36×(
+
)
=36×
+36×
=24+6
=30;
(2)0.65×14+86×65%
=0.65×14+86×0.65
=0.65×(14+86)
=0.65×100
=65;
(3)42÷[14-(50-39)]
=42÷[14-11]
=42÷3
=14;
(4)2.25×4.8+77.5×0.48
=2.25×4.8+7.75×4.8
=(2.25+7.75)×4.8
=10×4.8
=48.
點(diǎn)評:考查了運(yùn)算定律與簡便運(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)算定律簡便計(jì)算.