People often check out the [ Examples ] first to see the extent to which math notation can really be displayed on the internet and perhaps find the example that fits their situation. If you have a specific symbol you want to display and want to just find how it is done perhaps look below the examples to find the symbol. If you hold your pointer over the symbol for long enough, it will display the text you type in the editor to get the symbol.

I think the coolest thing about this editor is that you can mix regular text with math text. Anything you want interpreted as mathtext needs to be enclosed in ` ` or $ $ or if the double spacing feature is checked above the box you enter your ideas, you can surround your math text with double spaces.