解:(1)

÷(5-3×

),
=

÷(5-2),
=

÷3,
=

×

,
=

;
(2)84×0.25+

×16,
=84×0.25+0.25×16,
=(84+16)×0.25,
=100×0.25,
=25;
(3)48×(

-

+

),
=48×

-48×

+48×

,
=16-24+12,
=4;
(4)

÷

-

×

,
=

×

-

×

,
=

-

,
=

;
(5)7.8×101,
=7.8×(100+1),
=780+7.8,
=787.8;
(6)(1-0.8×

)÷

,
=(1-0.6)÷

,
=0.4×

,
=0.5.
分析:(1)先算括號(hào)內(nèi)的乘法,再算括號(hào)內(nèi)的減法,最后算括號(hào)外的除法;
(2)把分?jǐn)?shù)化為小數(shù),或者把小數(shù)化為分?jǐn)?shù),運(yùn)用乘法分配律簡(jiǎn)算;
(3)運(yùn)用乘法分配律簡(jiǎn)算;
(4)先算除法和乘法,再算減法;
(5)把101看作100+1,運(yùn)用乘法分配律簡(jiǎn)算;
(6)先算括號(hào)內(nèi)的乘法,再算括號(hào)內(nèi)的減法,最后算括號(hào)外的除法.
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)算律簡(jiǎn)便計(jì)算.