一个小型计算器，实现了数值的加、减、乘、除运算。-A small calculator, the realization of the value add, subtract, multiply, with the exception of computing.

此程序可以进行简单的数值运算，但还有些不甚完善，还望指教-This procedure can be a simple numerical computation, but some are not very perfect, but also look Zhijiao