The phrase the addition of is awkward. And I've only seen words and math figures combined in a sentence in math text books, not in ordinary writing.
We would probably say (or write) something like:
- Two and two is four.
- Adding two and two gives you four.
- Two and two makes four.
- Two plus two equals four.
- If you add two and two, you get four.
- You can add two and two together to get four.
Does that make sense? There are many possibilities.
PS - There are many different and conflicting rules about when to use digits (4) and when to spell out numbers (four). As with all conflicting rules of English, the only important thing is to be consistent.