考點(diǎn):整數(shù)四則混合運(yùn)算,運(yùn)算定律與簡(jiǎn)便運(yùn)算
專題:運(yùn)算順序及法則,運(yùn)算定律及簡(jiǎn)算
分析:(1)(3)(5)利用乘法分配律簡(jiǎn)算;
(2)先算加法,再算除法,最后算乘法;
(4)先算除法,再算乘法,最后算減法;
(6)先算除法和乘法,再算加法.
解答:
解:(1)(30+4)×25
=30×25+4×25
=750+100
=850;
(2)500×[(280+80)÷6]
=500×[360÷6]
=500×60
=30000;
(3)102×35
=(100+2)×35
=100×35+2×35
=3500+70
=3570;
(4)848-800÷16×12
=848-50×12
=848-600
=248;
(5)53×28+72×53
=53×(28+72)
=53×100
=5300;
(6)972÷18+35×19
=54+665
=719.
點(diǎn)評(píng):整數(shù)混合運(yùn)算的關(guān)鍵是抓住運(yùn)算順序,正確按運(yùn)算順序計(jì)算,適當(dāng)利用運(yùn)算定律簡(jiǎn)算即可.