 I'm here at the beach and I'm going to use these shells to explain the language of addition. If I have one shell and I add another shell, then I have two shells. When we're adding things, we use specific language. I can write my addition problem out with words 1 plus 1 equals 2. I use the same language whether I write the problem with words or with numbers. 1 plus 1 equals 2. These are the numbers 1 and 2. This is a plus sign. This is called an equal sign. When I write my problem, I can write it with words. I can write it with numbers horizontally. Or I can write it with numbers vertically like this. I read it the same way. 1 plus 1 equals 2. 1 plus 1 equals 2. I use the same language whether I'm writing single digits or reading single digits or multiple digits. For example, 10 plus 10 equals 20. 100 plus 100 equals 200.