Math notes: Not easy.

I noticed that in my Algebra II classes and my Calculus classes, students don’t take good notes. Some don’t take notes at all, some take really sporadic notes, some use scrap paper to do the “check yo’self” problems I put up after teaching a concept — to test to see if they get the concept and can do a simple and a somewhat more complicated problem. Then there are the few that take really amazing notes.

My first reaction was: what the heck are you thinkIng?

In both classes, I’m starting off the year not using the book heavily, so their notes are their primary source of material.

But then I had three subsequent thoughts, which tempered how I thought about and approached the situation:

(1) Students learn differently, and they know how they learn best better than I do.

(2) Students might not be used to having a teacher use SmartBoard exclusively, and having the ability to download the class notes each day changes things dramatically. Now the students have the ability to listen, think, and absorb instead of having to listen, think, and absorb all while frantically writing.

(3) No one has probably taught students how to take effective notes in math class, which explains why most of them just write down equations.

Instead of giving my “I’m disappointed in you” talk to students — admittedly, my first reaction — I decided to take a different course.

I decided to deal with my calculus students first. On Thursday, I went about teaching function transformations, and ten minutes into class, I stopped the class mid-sentence and told everyone to exchange their class notes with their desk partner. I asked each person to assign a grade to the notes for the day.

Unsurprisingly, some students had absolutely nothing written down, some had absolutely gorgeous notes, and most had some chicken scratch or just a series of equations written down.

I had students whisper the grade they assigned to the notebooks to the owner of the notebooks. I made some jokes, they made some jokes, and we diffused the atmosphere, which was tense. Initially a lot of people felt like they were caught with their pants down. They thought it was a pop quiz and the grade was important. I told them I wouldn’t ever hear the grade.

We used this to launch into a discussion of notetaking. I prompted three questions:

1. How do you take notes?

2. How does my using Smartboard everyday and uploading it change how you take notes?

3. Why do we take notes?

Different people had different strategies they shared when answering 1 and 2. The four things I emphasized/brought out in the discussion:

1. Different people learn differently and hence take notes differently, and until I see you start slipping, I’m not going to get on your case. But learning how to take good notes in math classes is an important skill so you might want to get on it now.

2. Keeping your notes organized (by date!) and neat can help you a lot.

3. You don’t need to take notes on everything. But when we’re first learning a concept, you want to really put a lot of attention into how you’re taking notes.

4. WORDS! WORDS! WORDS! A math notebook needs WORDS to explain each step, each tricky point, each concept. If you try to study from a series of equations without any words, you’re going to forgot why we were studying those equations or doing each step or technique. You need to understand the concepts we’re learning and words are key.

My two calculus classes meet either first or last period most days (we have a weird daily alternating schedule, but for some reason, my calculus classes always end up first period when everyone is dog tired and still waking up or last period when everyone is beat from the day and ready to go home.

I didn’t really let students answer “Why do we take notes?” even though I put it out there. They were going to come up with obvious. I wanted to say the slightly less obvious.

The number one reason: TAKING NOTES KEEPS YOU AWAKE.

The number two reason: TAKING NOTES KEEPS YOU ACTIVELY ENGAGED WITH THE LESSON.

I presented these with some humor, too. We talked about these ideas, and then moved back to the lesson. From start to finish, this aside took only 10 minutes. I noticed, at least for that day, students were being a lot of conscientious about what they were writing down and how they were writing it.

(I am probably going to have this “stop what you’re doing and exchange your notes with your partner” moment every so often.)

I’m going to deal with my Algebra II students’s notes next week, and slightly differently. They are younger, and me preaching to them won’t be as effective. So I asked the help of one of my students from last year, who took the most beautiful notes, wrote the most beautiful homework (with words and answered word problems with complete sentences!), and was always engaged in class. I’m having him come to my class and talk with them about his strategies for succeeding in my Algebra II class last year. How he studied from the book, how he took notes, how he did his homework, etc.

He met with the learning specialist last Friday to just hash out his ideas and get them in order, but these are his words. I didn’t tell him what to say, how to say it, anything. He has 5-10 minutes of time to say whatever he wants.

I don’t know how it’ll work. But I’m hoping that it’ll be an early wake up call to my class.

With that, I’m out.

UPDATE:

So my former Algebra II student said this is what worked for him:

1. Read the section BEFORE going to class, so it at least looks familiar
2. Take notes on the bolded terms in the book (e.g. “leading term”) — the math terminology
3. Try every problem to the furthest, even if it seems like it’s going nowhere. Because it might go someplace good, and if not, it’s fun to see how far you can get.
4. Write the entire solution to problems done in class, even if you know the process. Writing things down helps.
5. Ask questions, but wait until the teacher (me!) finishes his thought; the question may be answered if you give the teacher a chance.
6. Make a formula page, with all the formula we learn.
7. Study 2 days before the quiz, not the night before.

M45 and M46

Two new Mersenne Primes have been in the news recently. (Mersenne Primes are prime numbers of the form 2^n-1.) Finally, finally, after their primality (primeness?) was independently verified, they were revealed to the rest of the world:

M_{45}=2^{37,156,667}-1 and M_{46}=2^{43,112,609}-1.

There was a lot of speculation about the number of digits that these numbers would have. Not least for the fact that the first person to find a Mersenne prime with more than 10,000,000 digits would win $100,000. And indeed, the newly discovered primes have 11,185,272 and 12,978,189 digits respectively.

To put that in perspective, The Math Less Traveled shows that if you write out the number of atoms in the universe, that number would have a paltry 80 digits.

Of course, I think: how can I use this in my own classes? We don’t really talk about primes in Algebra II, Calculus, or MV Calculus. However, we do talk about logarithms in Algebra II.

Check it out.

How do you think we know how many digits are in M_{45} and M_{46}? It’s a simple application of logarithms.

We know that that a number is written in the form 10^N, it has N+1 digits (if N is an integer). Think about it: 10^1 has 2 digits; 10^3 has 4 digits; 10^5 has 6 digits.

If N isn’t an integer, it’s just a hop skip and jump away to saying that the number of digits is the next higher integer. So if we have 10^{3.1}, we have 4 digits.

Where do logarithms come into play?

Well, 2^{37,156,667}-1 has a certain number of digits. Since that 1 probably won’t affect anything since it’s such a huge number, we will ignore it. How many digits does 2^{37,156,667} have? Let’s use what we just discovered:

2^{37,156,667}=10^N

Then solving for N, we get N=37,156,667\log(2) \approx 11,185,271.306. Hence, we know there are 11,185,272 digits.

And a good question for the really ambitious student is to ask: can we be sure we can ignore that 1? (Answer: yes.)

(You can find the number of digits for M_{46} in the same process.)

You know it’s a bad sign…

You know you’re a bit rusty from the summer when a teacher asks you to — without using L’Hopital — to prove that:

\lim_{x \rightarrow \infty} \frac{\ln(2x)}{\ln(3x)}=1

And you are like, oh, that’s easy.

And then — after two false starts — it takes you 3 minutes to figure out.

Just remember: you are a calculus teacher.

I’m going to say it again: you are a calculus teacher.

Maybe if I say it enough times, it will be true.

(more…)

I don’t wears rose-tinted glasses

Every so often, I get a reminder of how completely different this independent school world is to the rest of the universe of schools out there. I guess after my first year in this microcosm, the shock and infinitude of differences have become so naturalized that I fail to recognize the weirdness, except when something jars me out of this strange reality.

Then you’ll usually hear me mutter “back when I was in school…”

And Sarah and Jackie’s comments to my last post did exactly that. I spoke about letting students out of my classes a few (not many) minutes early, if they finished and checked over a quiz. How is that even possible?

Let me paint a scene for you.

A school where there are no hall passes, no late passes, no detentions, no bathroom passes [1]. Students, when they have a free period or two, can sign out and leave the building. To get lunch, to get coffee, to enjoy some fresh New York air. Sometimes students sign out three our four times a day. We send our official attendance to the main office only once daily — after homeroom — and then teachers are responsible for keeping track of their classes attendance. Students are trusted that they’ll be where they need to be.

Not that there aren’t the occasional breaches of trust. A substitute comes and a student sneaks out of class. A student skips out on a gradewide meeting. Students who aren’t allowed to sign out — because of being late to school too many times or being put on academic probation — sometimes do sneak out. (Not on my watch, mind you.)

But they are occasional, and definitely the exception.

Right now, as I type, I’m sitting with my laptop at the sign out table in the front entrance. Students come by to say hi as they walk to Chipotle for lunch. I often get to have really nice conversations with teachers who walk by.

It’s a different world from what I grew up in, where our bathroom passes were toilet seat covers spraypainted in neon colors, where we had official pink hall passes, and where there were detentions for being late to class too many times. I guess that’s my “back when I was in school…” moment.

There are amazing benefits to working at my New York City independent school. And, as you would suspect even though I don’t write about them here, there are problems too. I don’t see my school through rose-tinted glasses. Seriously, I don’t. Still, I have a lot of admiration for this community that has been cultivated over the past hundred and some years. This school does something right… a lot of somethings right.

The mathematical key

I gave my first official quiz today in my Algebra II class. Since so many of my students have 50% extra time accommodations, I designed a 30-35 minute quiz and let the class take the entire 50 minutes. Usually there are a number of students who finish early.

Before students turn in their quiz, I tend to say “are you absolutely, absolutely sure you want to turn this in? Once it’s in my hands, I won’t hand it back, and it tends to be exactly 1 second after students hand in a quiz that they realized they made a mistake and want to check over the test again.” Except for those with some sense of usually false bravado, they wisely go back and check over their work.

But I’ve come up with a good way to keep students occupied once they’ve finished their test. I put up a problem — somewhat based on what we’ve been doing but *just* different enough that students will be forced to make a new conceptual leap on their own. If they show me the right answer, with correct work, I let them leave class a few minutes early. A luxury, for sure. The solution to the problem becomes their key out of my class.

Today in Algebra II, we had a quiz that covered — among other topics — inequalities. Students learned simple linear inequalities and how to solve them. So, for the challenge problem, I put:

Find and write in interval notation where: x^2+4x+3 \leq 0.

Two of them got it. Most of the rest of the class wanted to get it. I liked them thinking about problems that are just beyond what we’ve done.

Learning styles in our faculty meeting

Today we had our upper school faculty meeting (read: high school teachers meeting). The topic: learning styles. It was led by our really wonderful — and capable — and amazing learning specialists.

In the meeting were two activities I want to talk about.

One is we had a panel of students (mainly seniors) come in and give us — without using any teachers’ names — their opinion of what works for them in a class. Some things they noted were that doing problems over and over (drill practice) worked for them in math. And having teachers pause every so often for students to spend two minutes (no more!) doing a “check in” problem, or discuss a new concept, was useful. They also discussed the importance of pacing, and having a really explicit lesson plan (“by the end of today, you will be able to …”).

I thought having students give their perspective was so much more powerful than anything else we could have done for this meeting. (See this previous post for more: A letter sent back in time.) I would have actually loved a bit of a Q&A with them. (I really wanted their candid perspectives of group work; what goes through their head when the teacher says its time for groupwork, and how the dynamic actually works out in most of their classes.)

The second activity was less impressive, and actually a little frustrating. It was an activity where we had to answer questions, and walk around the room, to determine what kind of learner we are: kinesthetic, auditory, or visual. And even though it was mentioned that these categories had gradations, and that no one fits perfectly in any of these categories, we were asked to discuss how our own learning style affected the way we teach.

The problem is, I had watched this video that had been circulating through the blogosphere in August, and I I really buy into the message.

(Read the comments at Eduwonkette for some good stuff.)

So I’m not sure how to deal with the concept of learning styles. And according to the video, I’m not sure that should really be the central focus of how I plan my lessons.

Monday Math Madness 15

My favorite* online math puzzle contest — Monday Math Madness — has decided to use a problem that I submitted for a previous contest.

CHECK IT OUT HERE!

*It’s really the only one that I know. But that shouldn’t be taken disparagingly; the problems are just hard enough that you have to make one really rewarding conceptual leap, and just easy enough that with enough perseverance you know you can conquer it.