Lots of Links

For months I've been saving cool things in tabs in my browser. I think I was up to over 80 tabs when I started cleaning up yesterday. Here are the goodies...

• Trisect the Angle (using origami axioms)
• Growth Mindset (a conversation with Neil deGrasse Tyson)
• Denise Gaskins on Understanding Math (She references an article by Richard Skemp that differentiates between 'instrumental' and 'relational' understanding.)
• What are sigma levels? (statistics)
• A new pentagon for tiling the plane
• Project Pentagon (Christopher Danielson is playing around, and thinking about the math.)
• Fundamental Theorem of Calculus with proofs and an applet
• What is a radian? (geogebra applet)
• Teaching students to work well in groups
• The Differentiation: A Survivor's Tale
• John Wallis, Pi, and Quantum Theory (I need to read this again, and the next one)
• Ramanujan and Fermat's Last Theorem
• Is 5x3 Five Threes or Three Fives? (Scientific American)
• Steven Strogatz, in Scientific American, on Einstein's First Proof (my favorite proof of the Pythagorean Theorem, based on symmetry)
• Using theater exercises to teach math (Malke would like this!)
• Trig graphs on Desmos (using their new activity builder)
• If you can't explain it, does that mean you don't understand it?
• What it means to slow down a (calculus) problem
• youcubed.org is Jo Boaler's new site (her new book is Mathematical Mindsets, which I hope to review soon)
• A video on the Konigsberg Bridges Problem
• Turtle Triangles (on programming using turtle)
• It takes courage to play in a world that does not play
• High school students playing with blocks (3D visual sequences)
• Making related rates relevant by using students' names
• Which one doesn't belong? (with polynomial functions)
• Pam Sorooshian on emotions and math
• A message to the aliens
• Kepler, Napier, and the Third law (I'm trying to learn more of the history of calculus, to help me teach calculus more effectively. This article is good.)
• Function flip books (I thought I was done, but twitter is dangerously good!)

Games, Puzzles, & Problems

• Chat Noir (Can you corral the cat? I did it once. Can't do it again.)
• Drips (a nim game)
• How many sides of a pentagon can you see?
• A very hard truth and lies logic puzzle
• Factor Grid (I wonder if I could make up my own versions of this)
• Some good problems of the week (this site changes each week)
• A simple trig challenge (I need to save this for my precalc class)
• Factory RatiosSpeed of sound
• Blermions (an approach to some geometry questions)
• Can you make this graph?

I have to admit that I skip the Intermediate Value Theorem when I teach Calc I (please tell me if you think I'm short-changing my students), but here are two great posts about it. If you ran a race at an average pace of 3:07 per kilometer, did you run any single kilometer in exactly 3:07? (from Scientific American) and an activity using Desmos (from Christopher Danielson).