Teaching with scratch

I have used Scratch in my seventh grade pre-algebra class, a different level than what you are trying but maybe this will be helpful anyway.  Have fun!

I looked at the topics in the required curriculum and asked myself where using Scratch would enhance student learned of specific concepts.  I chose three areas for the kids to make their own projects and a few others where a demonstration project made by me would help in the teaching. 

1.  Coordinate geometry: project was to make their initials using only pen and "go to x, y" commands.  First they did this in quadrant one, then they had to draw three more sets of initials in the other quadrants, same distance from the x,y axis as the first ones.  It was very hard for some of the kids to do the transfer, and told me a lot about their visual/spatial understanding.

http://scratch.mit.edu/projects/room209/321638

2.  Similarity:  project was to make a very simple quadrilateral-based character, then use a formula to enlarge or shrink it.  They made variables with sliders to show that if you only mess with one coordinate, the image is not similar to the orginal.

http://scratch.mit.edu/projects/ExpoSchool/867742

3.  Geometry terms:  The geometry at this level included lots of vocabulary, so I had the kids make a Scratch dictionary defining some of the terms and illustrating them with an animation.

http://scratch.mit.edu/projects/room209/913317

Project demonstrations:

Equations with variables represent real situations

http://scratch.mit.edu/projects/room209/672035

http://scratch.mit.edu/projects/DrSuper/676759

Probability

http://scratch.mit.edu/projects/room209/581

Graphing equations

http://scratch.mit.edu/projects/DrSuper/323304

Exponents

http://scratch.mit.edu/projects/DrSuper/300519