Common Core Standards: Math
1. Interpret expressions that represent a quantity in terms of its context.
The only way that could be more general is if it said, "Do things to things in terms of other things." Luckily, we have just a smidgeon more to work with.
At its core, this standard wants students to start thinking of math as a language, not a pile of numbers. Just like any other language, math can help us communicate thoughts and ideas with each other, but students need to know the basics before they can really understand it.
Your students probably already have some idea of what an expression is in a general sense. Start from this point. At its simplest, an expression is a thought or idea communicated by language. In the same way, a mathematical expression can be considered a mathematical thought or idea communicated by the language of mathematics.
Emphasize that mathematics is a language, just as English, French, German, and Pig Latin are languages. Students should use the ocabulary-vay of athematics-may correctly to become fluent in it. After all, the best way to learn a new language is to immerse yourself in it.