a/2067583

1.3/7×49/9-4/32.8/9×15/36+1/273.12×5/6–2/9×34.8×5/4+1/45.6÷3/8–3/8÷66.4/7×5/9+3/7×5/97.5/2-(3/2+4/5)8.7/8+(1/8+1/9)9.9×5/6+5/610.3/4×8/9-1/311.7×5... (1)168+36-36+32=(2)153-5×14+83=(3)50×5÷50×5=4.用简便方法计算:(1)3786-499(2)32×25×125(3)1653-338-662(4)7987+350+2013+450(5)38×38+62×38(6)452+99×452(7)20... 408-12×24(46+28)×6042×50-1715÷532+105÷5(108+47)×52420×(327-238)(4121+2389)÷7671×15-974469×12+1492405×(3213-3189)5000-56×23125×(97-81)6942...