2001÷2001又2001/2001=2001/[(2001×2002+2001)/2002]=2001/[(2002×2002)/2002]=2001/2002 633×210-（5697×28.3+717×569.7）×11/90=633×210-（5697×28.3+71.7×5697）×11/90=633×210-（28.3+71.7)×5697×...额，第一个简算你落了一个“+1/2003”