2nd hour: Went over the worksheet via quasi-traditional "Whiteboard Parade." Groups whiteboarded a couple of problems each, then everyone had the chance to walk around and go over the boards at their own pace (no formal presentations).
5th hour: I 'rewarded' the class with an extra day to work because I was so happy they were actually working for a change. I also pointed out what I was doing to them (that their efforts were being recognized and I was slowing the pace of the class down for them as a result). I'd never been against slowing down, but if the class isn't going to do anything, then there's no reason to go slow.
6th hour: I tried to do the WB parade like in first hour, but it doesn't work as well with this group. They might get the problems whiteboarded, but everyone just sits in their seats and talks with their friends instead of checking their work and correcting themselves. I tried reminding them of the next day's quiz, but they either think they get it (they don't), or they just don't care.
I'll figure something out eventually.