Addition is the process of putting numbers together. 加法是把数字放在一起的运算过程。

　　Addition is one of the simplest things in math. 加法是数学中最简单的运算之一。

　　It is very basic in math as well. 它在数学中也是非常基础的。

　　Everybody knows the + sign. 每个人都知道加法符号。

　　The + sign is one of the math symbols. 加法符号是一个数学符号。

　　+ means more in Latin. 加号在拉丁文中是更多的意思。

　　When was the + sign first introduced? 加号第一次被引入是什么时候？

　　In 1557, one German mathematician introduced the + sign for the first time. 1557年，一位德国数学家第一次引入了加号。