Math Blaster: Geometry
Geometry Blaster is from the Davidson company, a pioneer in educational software. Almost all Davidson products work on the guiding principle that education comes easier if disguised as a game.
This app begins with the introduction of two animated characters, teenager Andi and her sidekick, Zoid, who is made out of geometrical shapes. They travel to a planet where the evil Geometrons have stolen the third dimension, leaving everything flat. Your job is to win back the 3D by helping Andi answer questions.
At first glance it might seem a little juvenile. However, there is nothing childlike about the questions and problems in Geometry Blaster, even on its "novice" level. You can't bluff your way through without knowing the difference between an acute and obtuse triangle.
Luckily, Geometry Blaster comes with a series of 52 lessons, each of which teaches a basic concept and then lets you practice putting it to use by solving sample problems.
I was a little put off, at first, by the fact that all the work is done on the computer screen. The act of working out problems with pencil and paper always seemed kind of elegant. But I learned rapidly by fooling around with Geometry Blaster, and after a few lessons I felt confident enough to start helping Andi and Zoid save the planet.