计算大整数的四则运算（+，-，*，/），可以运算至少上百位的四则运算，采用DOS界面，速度很快，不会让你等1秒钟。-Calculation of large integer arithmetic operations (+,-,*,/), be at least hundreds of 4-bit computing, the DOS interface, fast, will not let you, such as 1 second.