Check out my presentations!
Create your own Penrose Tilings (like the banner!)
Cryptograms - break the code!
Sudoku and all its variations! (Jigsaw-doku, letters, squiggly, Sudoku-X, Samurai (5 interconnected Sudokus!!!), 16x16... Requires flash, but there are apps for phones!)
Tangrams - made for kids, but still fun to play!
YouCubed - a nonprofit housed at Stanford to help instill mathematical learning and math enjoyment to all - educational website, but full of fun thought activities.
Mathigon - learn about all kinds of fun math in an interactive way!
Donald in Mathmagicland - Watch a classic and one of my favorite movies about MATH!
Many of these I've sourced from Math Discord Servers and my own research
OpenLogicProject - free books on various topics in Logic
Calculus (Lev Tarasov) - Free calculus book, translated from Russian
Abstract Algebra (Judson)
www.sagemath.org - a grapher, visualizer, calculator (like MATLAB or Mathematica, but free!)
http://www.studentguide.org/a-complete-list-of-online-math-resources/
Paul's Online Notes: Math Prof sharing his teaching notes on various classes
University of Sydney: various topics
If you know of more resources, email me! I'd love to add to this list!
Top Banner: Penrose P2 Tiling, By PrzemekMajewski - Own work, CC BY-SA 4.0
Penrose tiles are an example of aperiodic tilings of the plane (they can fill up space, but not symmetrically like regular bathroom tiles!)