解:(1)8000-2520÷24×72,
=8000-105×72,
=8000-7560,
=440;
(2)

12,
=


÷12,
=

12,
=54;
(3)[3-(

0.75)

]×

,
=[3-2×

]×

,
=

,
=

,
=

;
(4)0.75×

,
=0.75×(

12),
=0.75×(16-12),
=0.75×4,
=3;
(5)1



,
=(

)-(

),
=(

)-(

),
=

,
=

,
=

,
=

.
分析:算式(1)根據(jù)整四則混合運(yùn)算的運(yùn)算順序按照四則運(yùn)算的計(jì)算法則進(jìn)行簡算;
算式(2)根據(jù)分?jǐn)?shù)四則混合運(yùn)算的運(yùn)算順序按照分?jǐn)?shù)四則運(yùn)算的計(jì)算法則進(jìn)行計(jì)算;
算式(3)根據(jù)分?jǐn)?shù)四則混合運(yùn)算的運(yùn)算順序按照分?jǐn)?shù)四則運(yùn)算的計(jì)算法則進(jìn)行計(jì)算;
算式(4)應(yīng)用乘法分配律進(jìn)行簡算;
算式(5)根據(jù)加法結(jié)合律和減法運(yùn)算性質(zhì)進(jìn)行簡算.
點(diǎn)評:此題主要考查整數(shù)、分?jǐn)?shù)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)算律簡便計(jì)算.