一个计算器，利用它可以进行简单的四则运算（加、减、乘、除、开方）等，但仅限于十进制下，此外还可以进行（八进制，十进制，十六进制）之间的相互转换。-A calculator, use it for simple arithmetic (add, subtract, multiply, divide, square root), etc., but only decimal, the addition can also be used (octal, decimal, hexadecimal) between conversion.