简单计算器， 计算100以内的加减乘除的简单 GUI界面(Calculator Simple calculator, calculate less than 100 less than multiplication and division of a simple GUI interface)

javaFX计算器简单实现了加减乘除、逗号、开方、求到数的操作(The javaFX calculator simply implements the operations of addition, subtraction, multiplication, division, comma, square-opening and number-finding.)