MathSymbols
This is the repository for the Mathematical Symbols and Notation pdf (written in LaTeX).
The pdf is a comprehensive list of general and widely-encountered mathematical symbols and notation that is useful anywhere from middle-school to high-school, maybe even college. The first section provides a quick definition of said symbols. A more comprehensive list of formal and exact definitions is planned in the future. Print the pdf and use it however you like, I'm not the boss of you :P.
The MathSymbols file is mainly written using ShareLaTeX which is a neat and handy online workspace for making and editing .tex files with a compiler on the side.
Contributing
If you would like to make a suggestion or change to the pdf, simply create a new issue with a list of the exact details and things you'd like to see inside the pdf file.