分析:(1)按照加減混合運(yùn)算順序,從左往右計(jì)算即可;
(2)按照整數(shù)混合運(yùn)算順序,先算除法,再算減法;
(3)按照整數(shù)混合運(yùn)算順序,先算括號(hào)內(nèi)的減法,再算乘法,最后算加法;
(4)運(yùn)用乘法的交換律、結(jié)合律進(jìn)行簡(jiǎn)算;
(5)運(yùn)用乘法的分配律進(jìn)行簡(jiǎn)算;
(6)運(yùn)用乘法的分配律進(jìn)行簡(jiǎn)算;
(7)運(yùn)用減法的運(yùn)算性質(zhì)進(jìn)行簡(jiǎn)算;
(8)變形為25×4×4,簡(jiǎn)便計(jì)算即可;
(9)根據(jù)連除的簡(jiǎn)算方法計(jì)算.
解答:
解:(1)272-44+85 =228+85 =313;
(2)230-130÷10 =230-13 =217; |
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(3)144+(57-12)×2 =144+45×2 =144+90 =234;
(4)250×15×4 =(250×4)×15 =1000×15 =15000; |
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(5)99×45+45 =45×(99+1) =45×100 =4500; |
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(6)17×23-23×7 =23×(17-7) =23×10 =230;
(7)289-125-75 =289-(125+75) =289-200 =89;
(8)25×16 =25×4×4 =100×4 =400; |
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(9)3200÷4÷25 =3200÷(4×25) =3200÷100 =32. |
點(diǎn)評(píng):此題主要考查整數(shù)的四則混合運(yùn)算的運(yùn)算順序和應(yīng)用運(yùn)算定律進(jìn)行簡(jiǎn)便計(jì)算.