Scratch and 8th Grade Geometry

http://welovetypography.com

From twitter I found out about the K12 Online Conference. In particular about a Scratch session by Chris Betcher (@betchaboy on Twitter).  The session has a nice 22 min video about using the Scratch programming language with Year 5 students.  Very worthwhile info in a sitcom sized bite.  Chris also has a Scratch wiki devoted to getting students going with Scratch, and all the resources you need to get going.  Scratch is perpetually one of those things I'm going to investigate when I have obtained some sparemomentium.

I got a chance to work with a local 8th grade teacher who's looking into Geogebra.  He sent me some of the state standards he was interested in exploring, and I made up a couple sketches to play around.

The first is just a demonstration of the area formula for a parallelogram.  It seems so unreasonable that all parallelograms with the same base and height have the same area.  That connects with one of Geogebra's strengths to me - providing essentially infinite examples so that students can notice.

Webpage and geogebra file

The next is probably pointless.  I was considering how to make a dynamic area measuring sketch.  I thought the advantage would be being able to change the figure, and easily check your answer regardless of how you've changed the shape.  I used sliders to build the shapes so that the distances would be nice.
Webpage and geogebra file

The third sketch is for similarity - I'll post that later this week with the world's easiest activity.