Author: samjshah

Michelle Rhee

I’ve been hearing a lot about Michelle Rhee, Chancellor of Education of the DC school system. I haven’t read anything about her, though, but after reading this Time article, I want to read more. Something to whet your post-Thanksgiving appetite:

She says things most superintendents would not. “The thing that kills me about education is that it’s so touchy-feely,” she tells me one afternoon in her office. Then she raises her chin and does what I come to recognize as her standard imitation of people she doesn’t respect. Sometimes she uses this voice to imitate teachers; other times, politicians or parents. Never students. “People say, ‘Well, you know, test scores don’t take into account creativity and the love of learning,'” she says with a drippy, grating voice, lowering her eyelids halfway. Then she snaps back to herself. “I’m like, ‘You know what? I don’t give a crap.’ Don’t get me wrong. Creativity is good and whatever. But if the children don’t know how to read, I don’t care how creative you are. You’re not doing your job.”

Linear Regressions

In Algebra II tomorrow, I’m going to finish up talking about linear regressions. And in honor of that, I’ve created their Thanksgiving homework: a worksheet.

I’m having students

1. pick 10 words
2. check to see how many wikipedia hits these words got in October 2008
3. check to see how many google hits there are for those words

(Example: “monkey” was looked up 122,694 in October 2008 and has about 140,000,000 google hits.)

Then they’re going to see if the data looks linear, and calculate a line of best fit, and use it to predict.

Even though the worksheet needs a lot of work in terms of the questioning and phrasing (I am so tired that I couldn’t think of great questions… I just felt the need to pound this out), I still think this is one of my better activities.

If you want: 2008-11-25-worksheet-on-linear-regressions

Perhaps I’ll compile all the data from all the students and we’ll have a larger data set. We’ll get to talk about outliers (e.g. if you look the word “water” up, things are crazy). I personally am curious what will happen.

(FYI, for the 10 words I chose, I got an r value of about 0.7.)

Taking the Twitter Plunge

So I’ve decided there is possibly a vibrant teaching community that I’m not familiar with, because I had decided to ignore Twitter while getting the year in order. So here I am, going to take the plunge.

My twitter page is: http://twitter.com/samjshah

I want to join a group of high school math teachers. I found a whole bunch of blogs by math teachers that I follow regularly. Let’s see if I can find the same on Twitter.

And if you have a Twitter account and want to say hi, feel free! Right now I’m twitter-lonely.

Kepler’s Laws

In my multivariable calculus class, we spent last Friday reading the textbook as a group, trying to understand the section on Kepler’s Laws. We got done showing that if there is a sun-like object and another object with a particular initial position and velocity, it will either fall into the sun, be an circle, be an ellipse, be a parabola, or be a hyperbola.

Today we were going to move onto using this result to derive the three Keplerian laws of planetary motion.

But then I decided to scrap that. Because even though we read the book and followed the text, line by line and equation by equation, we lost sense of what we were doing. We lost sense of the conceptual underpinnings for each equation. We didn’t know what motivated the book to make the moves it made. It’s largely the book’s fault, which is really unclear — if you’re a high school student and not used to having your book say “we leave this as an exercise to the reader.” (Seriously, it did that.)

One of the things you’ve heard me say is that I want to foster the skill of students learning to communicate math well.

So, I decided to scrap the plan of moving forward, and we’re devoting two or three days to

WRITING OUR OWN TEXT EXPLAINING THE DERIVATION OF KEPLER’S LAWS.

We started out the class outlining a basic structure to it (Part I: What we want to show; Part II: Initial Conditions; Part III: Gravitational Pull; etc.). Then the four students started talking about what they wanted to say. (One agreed to draw the diagrams we’re going to include in our text.) I just sat up front, and when they decided, I typed it up in my LaTeX editor — projected so that students could tell me to fix or reorder something. Sometimes I prompted them (“you told me to write \vec{v} but you never told the reader what that is” or “does it matter if the initial velocity weren’t orthogonal to the position vector?”). And it took us 50 minutes to get about a third of the way done.

But you know what? It is working. They’re talking, they’re thinking, they’re arguing with each other, they’re asking questions. And they’re learning to work through things, and explain them to someone else.

I was so pleased. Hopefully the next few days go as well.

Advice for using an online math textbook

In this Year Of Massive Transformations in my school (many new faculty, new administrative structure with loads new administrators, a new department head for me), we’re also overhauling the high school math curriculum. We’re really trying to come up with a great Algebra II/Precalculus sequence, and I’m involved with helping codify the non-accelerated track. We’re definitely switching textbooks (the one we’re using now is just too hard for the kids).

In our search, we came across an Algebra II textbook published by Holt. We liked the examples, the number and kinds of homework problems, the layout, and the sequencing. (Although we’ll deviate from the sequencing a bit.) The best part about it: if we buy the textbook (around $80), we get access to the e-book for 6 years for free. And from what I understood from talking to the representative, we can just pass on the password from student to student from year to year.

Our Student Council is soon going to be approaching department heads about getting e-books for some of the courses (the physical books are really heavy and expensive). It makes really good sense because we’re a laptop school! I’m going to request that the school purchase these books and charge students $20/year for access to the e-book. And then for students who want to borrow a physical textbook, they can get them from us.

But this all seems very logistically challenging. I can anticipate a few problems already (importantly: what do you do with the excuse “I didn’t have internet access where I was last night”?)

Which is why I bring this to you. Have any of you used online textbooks before? Anything I should keep in mind when making this decision? Any great benefits to it? Any great drawbacks?

And if you haven’t used online textbooks, what sort of problems would you anticipate?

Mathematics Illuminated & the Carnival of Education

1. The Carnival of Mathematics 43 is out. There’s some really great stuff there! Including a really wonderful problem for an Algebra II class! And a great way to do test review!

2. Today in my MV Calculus course, I was teaching curvature. One of my students asked for the dimensions of curvature. Love those sorts of questions! In any case, when I was looking online for some good resources, I came across this website which explains curvature — and a bunch of other really interesting math topics — to the layperson.

So, here’s my present to you: if you’re a math teacher and you have an extra class to introduce the ideas behind advanced mathematics, without going into all the equations and nuances, you have your lesson plan laid out here, at Mathematics Illuminated. Totally awesome stuff! Plus, if you register (for free!), you can stream videos on teach topic. Unfortunately, I haven’t been able to watch one yet, so tell me if you get a chance if the videos are any good in the comments.