创建一个计算器类，能够在同一时间完成两个数字的加减法。不太懂，原文：%。

Create a class Calculator, which performs the addition and subtraction of two Numbers at a time. The sample code explains the expected API.

youdao

创建一个计算器类，能够在同一时间完成两个数字的加减法。不太懂，原文：%。

Create a class Calculator, which performs the addition and subtraction of two Numbers at a time. The sample code explains the expected API.

youdao