问题提出：在应用电脑的过程中，往往需要使用计算器，来执行简单的运算，但系统提供的计算功能过于烦琐，而且有些程序并不提供计算功能。-Issues: the process in the application of computers often need to use the calculator, to perform simple arithmetic, but the computing system is too cumbersome, and some do not offer the