Sam Shah had asked, so here it is -- some piecewise lessons I've done in past, leading up to a debate on tax policies at the end of the income tax unit. This course I had only taught once, two years ago, as part of the NYC Math B curriculum. (Or, loosely following the Math B curriculum, I guess.)
Disclaimer: I didn't come up with all of these materials! Some of it I did (all of the extensive scaffolding, more or less, and some word problems). My colleague and friend, Tim Jones, from my previous school had taught the honors version of the same course before me, so I took a lot of the income tax stuff from him. (I had to add a lot of scaffolding for my regular 10th-graders though, and the unit ended up taking twice as long as his class did.)
Link to piecewise unit and link to income tax unit, dumped into viewable directories.
All the lessons are numbered in order (evidence to my organizational tendencies), so they should be easy to follow, but in some cases you'll find that I took two steps forward and one step back, because I had realized that my inherited (honors) version of the lesson was just too-much-too-fast for my kids. Have fun probing! If you have questions or comments, feel free to shoot them my way even though I don't teach much of this stuff anymore.