脫式計(jì)算:(能簡(jiǎn)算的要簡(jiǎn)算)
437×482+518×437=
8.07-1.65-2.35=
5.65×2.8+4.35×2.8=
40-3.16-(18+2.2)+10.6=
解:(1)437×482+518×437,
=437×(482+518),
=437×1000,
=437000;
(2)8.07-1.65-2.35,
=8.07-(1.65+2.35),
=8.07-4,
=4.07;
(3)5.65×2.8+4.35×2.8,
=(5.65+4.35)×2.8,
=10×2.8,
=28;
(4)40-3.16-(18+2.2)+10.6,
=40+10.6-(3.16+20.2),
=50.6-23.36,
=27.24.
分析:算式(1)和算式(3)運(yùn)用乘法分配律進(jìn)行簡(jiǎn)便計(jì)算;
算式(2)和算式(4)運(yùn)用減法的運(yùn)算性質(zhì)進(jìn)行簡(jiǎn)便計(jì)算.
點(diǎn)評(píng):此題主要考查整數(shù)、小數(shù)四則混合運(yùn)算,注意根據(jù)算式中數(shù)據(jù)的特點(diǎn),靈活運(yùn)用運(yùn)算定律和運(yùn)算性質(zhì)進(jìn)行簡(jiǎn)便計(jì)算.