xkcd!

Web cartoonist Randall Munroe answers simple what-if questions ("what if you hit a baseball moving at the speed of light?") using math, physics, logic and deadpan humor. In this charming talk, a reader's question about Google's data warehouse leads Munroe down a circuitous path to a hilariously over-detailed answer — in which, shhh, you might actually learn something.

Salman Khan talks about how and why he created the remarkable Khan Academy, a carefully structured series of educational videos offering complete curricula in math and, now, other subjects. He shows the power of interactive exercises, and calls for teachers to consider flipping the traditional classroom script -- give students video lectures to watch at home, and do "homework" in the classroom with the teacher available to help.

A short movie inspired by numbers, geometry and nature. Created by Cristóbal Vila, this video manages to explain how everything, from snails to flowers, is built according to predictable mathematical principles. Numbers have never been more sublime. Principles illustrated in the video include Fibonacci, Golden Ratio, Delaunay, and Voronoi.

Check out etereaestudios.com for more info.

This is a trick I did for my Nature of Math class at Biola University this afternoon. I like experimenting with mixing live action with video.