If you don't know LaTeX and don't want to learn it, you can use MathType to add equations and formulas to a Knote. These instructions will work for MathType 6.6 and later (which means they're Windows-only for now, since MathType 6.0 is the latest version for Macintosh).

• In MathType's Preferences menu, choose Cut and Copy Preferences:
  
• From the Equation for application or website section, choose Google Docs. Of course, Knotebooks isn't Google Docs, but MathType's Google Docs translator will work fine here.
  
• Create your equation in MathType, then select it and copy it.
  
  
  
• Now paste it into your Knotebook wherever you want it:
  
• That's really all there is to it. You can even mix Knotebooks' LaTeX with MathType equations in the same Knote if you want. For simple things like the Greek letter pi, it sort of makes sense to just use the built-in LaTeX for that. This is Knotebooks' built-in LaTeX and this is MathType's .How about the square root of 2? Still fairly simple to just type in: \sqrt{2}. This is the built-in LaTeX and this is MathType's . So you can choose which method to use -- MathType or built-in LaTeX.
• One final note. Any of the MathType equations or formulas you insert with these steps above, you can edit in MathType if you want. This is helpful if you have several equations that are similar, and need to change a variable or value or two, or if you just need to correct a mistake. Just click once on the equation, copy it, then paste it into MathType.
• Post a comment if you have any questions.