Well, I did better on the timing today, but still not good enough. I had one extra example built-in that I had to skip, and I had wanted to give the students a few minutes to work on five quick review problems in class but we didn't get to those either. On the positive side, I think they were reasonably engaged in what we did do (although it's awfully hard to tell with teenagers in a first period Algebra class that starts at 7:21 am).
We started with an opener (pdf) like usual. I really liked the first problem and I shared my thinking with them when we went over it. I'm struggling a bit, though, with my expectations on the other ones. At this point my assumption is that they should be able to do the third and fourth one fairly quickly and easily, as we've spent several days on this. And some students are definitely there, but just not as many as I had hoped. That's at least partially because they are (so far) choosing not to do some of the things I've asked them to outside of class. We're still in the stage where I'm giving them some leeway to figure this all out, but pretty soon they are going to need to step up if they're going to be successful with the variable schedule that our high school runs. Is it unrealistic to expect high school Algebra students to do problems 3 and 4, with a calculator, fairly quickly after several days of practice?
We then went through several applications of proportion and percent (lesson, pdf). Borrowing from Dan Meyer (I'm going to be writing that a lot), I started with a clip from The Bone Collector. The character played by Angelina Jolie needs to take a picture of a footprint before it gets washed away by the rain, but places a dollar bill in the picture first. I showed the clip and asked, "Why did Angelina do that?" We then talked about needing a reference for scale and how to use proportions to figure out the length of the footprint (see the lesson for a still from the movie clip). Tip: It's always helpful to get a $20 bill out and put it on the document camera - gets their attention. We then figured out the length of the footprint, which I think is kind of cool. (Figuring out the length of a footprint created on a stage somewhere in California eleven years ago just from a still picture? Yeah, I think that's cool.)
We then looked at similar triangles and the fact that the lengths of corresponding sides are proportional (didn't derive that or anything, just asked what they noticed). We then used that to try to figure out the height of our gym from a picture I had taken a week ago. I think some of the students really got this, but some of them just thought it was more noise. Not sure what to do about that.
The third example was some basic sampling, following up on our capture-recapture work from Friday. We talked about whether our class was a good sample for the question (yes for lunch, no for driver's license), and then I actually went across the hall to Mr. Swomley's class to get the actual number for the dog question. (Aside: not sure if the student are appreciating my humor or quirkiness yet.)
Due to time, I skipped the fourth example about the chemical formula for TNT. I thought that was a nice, quick connection to Chemistry, but my inability to plan for time correctly is killing me.
We then finished with the stock market example. I really thought this was a good one when I was planning it, and I think it worked okay just in terms of practicing percents, but I think perhaps the stock market isn't quite something most of them relate to right now.
The last page of the lesson includes the problems I was hoping to get them started on, but instead suggested they work on as part of their review for the assessment on Wednesday. Visit the post on the class blog for the description I gave them of the day and their full homework (more on the upcoming Skype session in a future post).