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 computing process.