1、专题训练有理数运算中常见的五种技巧技巧一巧分组1计算:(2)31(3)2(4)_2计算:1234567892019201920192019201920192019.3计算:3(9.5)(12)()(10)技巧二巧凑整4计算:36.54228263.46_5计算:118530.251.875.6计算:5.625321.技巧三巧分解7计算:2543_8计算:245(2)(5).9计算:.技巧四巧转化10计算:10(2)_技巧五巧用运算律11计算:()(246)()()_12计算下列各题:(1)60();(2)(354)(3)(354)(5)(3.54)(2).132解:原式1(2345)(6789
2、)(2019201920192019)(2019201920192019)2019100020192019.3解:原式3(9.5)(12)()(10)3(12)()(9.5)(10)(9)(1)8.4405解:原式118(50.25)(31.875)118(6)5117.6解:5.625321(5.625)(321)(5.6250.375)(321)671.728解:245(2)(5)(2)45(2)(5)()(45)(225)()991.9解:原式11.103116.12解:(1)60()60606012302543.(2)(354)(3)(354)(5)(3.54)(2)354(35)(3.54)(2)7087.08700.92.第 3 页