Go back to Add-ons in the Google Docs. You can get it for free at the Google Docs add-ons store. Learn how to insert equations into a Google document.
To open MathType to write an equation choose either Insertedit math equation or Insertedit chem formula from the Add-ons menu.
Fire up your browser and head to the Google Docs homepage. Select a cell and press Ctrl C to copy and press Ctrl V to paste. Heres a list of all the functions available in each category. As mentioned above if you need to insert a citation any kind of formula or even a service mark youll have to use subscript in Google Docs.