In the past few weeks I’ve been reading what others have been saying about Khan Academy and decided to watch some of the videos. Since I had forgotten about limits in calculus, I watched a video about that. I promptly fell asleep. His voice is pleasant enough, but I’m a visual person I need more stimulation than having a lesson scratched out on a blackboard. But I didn’t give up. I tried a video where I knew the subject well. On Monday we ran a blog post on the Pythagorean Theorem so I decided to see what Khan had done on this subject. Here is Khan’s version where he proves the theorem. And here is the Elevated Math version. (We just put this up on YouTube.) Khan’s proof takes around eight minutes while Elevated Math’s takes only a minute. You be the judge which is better. The big difference, besides the proof itself, is in production value. Along with the one minute explanation Elevated Math has another 19 minutes of instruction on right triangles, animated graphics, problem-solving, practice and immediate feedback. The Khan video is free while the Elevated Math lesson costs less than the price of a Starbucks cup of coffee.
“Back where I come from, we have universities, seats of great learning, where men go to become great thinkers. And when they come out, they think deep thoughts and with no more brains than you have,” as stated by the Wizard from Oz in 1939. According to him, a Th.D. diploma (Doctor of Thinkology) is all that is needed for Scarecrow to spout off the Pythagorean theorem (albeit his definition was slightly off). I think my middle school math students would have supported the Wizard’s notion that it takes some kind of diploma to be able to understand the theorem and recite it, but that was before the days of the Internet. Nowadays, anyone who has any kind web-surfing device and web access can find a wealth of information about the theorem. No diploma required! Just do a Google, Yahoo or Bing search.
Newly posted on YouTube is an animated illustration and explanation of the theorem. This is a short sequence from a lesson (M8.7) in the Elevated Math app. Another Elevated Math lesson (A18.4) uses the Pythagorean theorem in finding distance between two points. Elevated Math is in the App Store in iTunes.
In your Internet search you will find teaching videos that feature robotic teachers, boring lectures, great info with no people, waterwheels demonstrating the concept, Darth Vadar explaining the theorem, and even § Read the rest of this entry…