Javascript, like almost all other programming languages, uses native routines to do mathematical calculations. 
These native routines are generally perfomed either by the CPU or a 
math-coprocessing chip.http://support.intel.com/support/processors/pentium/google算的也是这个数http://www.google.com/search?hl=zh-CN&q=999999999999999999%2F1&btnG=Google+%E6%90%9C%E7%B4%A2&lr=
脚本语言不太适合做大数和浮点运算