# Monthly Archives: February 2013

## Getting the Quiet Class to Talk

The Problem

I’ve got one class that just doesn’t want to talk.  They’re great students and they all focus when I’m talking.  I think main reason they don’t want to talk is they don’t want to look like “know-it-alls” in front of each other, and so they won’t answer when they know the answer, and they’re even less likely to answer when they don’t know the answer.  Especially during white-boarding sessions, students just don’t want to talk.

My (Failed) Attempts to Fix the Problem

I’ve tried many different things to get them to start talking:

• White-boarding sessions
• The mistake game during white-boarding sessions (I was really excited about this one and it turned out to be a super-flop with this group… worked really well in Precalculus, however!)
• That extra-long awkward silence after asking a question
• I also had a day where they weren’t allowed to talk: they had to type into http://www.todaysmeet.com
• I’ve had them “think-pair-share” (write something down individually, share in groups/pairs, then share to the whole class)

And yet, it still feels like I’m sitting there waiting for them to discuss and share what I’m pretty sure they know.  Maybe they’re just not creative and don’t have any ideas worth sharing (yeah, right!).  Or maybe I’m not giving very good leading questions and too often I’m asking the “can you read my mind?” questions (much more likely).  But often times I’m asking questions like “what did you notice?” or “what did you find interesting?”.

The Setup

So recently I decided I would “light a fire” under them and force them to talk.  These are all great students who cared about their grades, so I let them do a white-boarding session where they shared the results of a mini-lab where they played around with colliding carts, changing the mass around and using a stopwatch and meter-stick to find velocity.  I never once gave them the word “momentum”–I let them figure out that’s what they were finding and observing.  They worked on their whiteboards for a whole class period (50 minutes) on Friday.  As they were working, I moved from group to group dropping hints and asking directive questions, but never addressing the class as a whole.  Many groups were making really good progress, but I knew they could go so much faster if they could share what each individual group discovered to the whole group.

The Fire Under Their… You Know

So when they came back to school the following Monday, we started a white-boarding session, but I told them two things that changed the whole game.

1. Each student had to make at least one comment about their board and/or ask a question of another group.
2. There was going to be a quiz following the white-boarding session.

I pointed out that the solutions to the quiz could be found throughout everyone’s whiteboards, though through understanding.  I.E. The questions were not going to be of the form “what was on Bobby’s whiteboard in the top right corner” but instead would require the students to understand what each axis and variable represented in each of the groups.  Here is the quiz to give you an idea of what I had hoped students would learn:

One of the things I found important that I hope is represented in the quiz above is how heavily I relied on their experiences (see #70 and 80).  The questions were also very open ended, so students could add more math as they felt necessary.

Another Attempt

More recently, I’ve heard a little about this “I notice, I wonder” way of getting students to communicate and open up in class, and so I just recently tried that and was pleasantly surprised by the results when using this collision simulator. Disclaimer: I haven’t read very much about it, so I know very little beyond asking the students to finish the sentence “I notice…” after they’ve seen a phenomenon.  However, it does remind me of how important vocabulary is when helping students think divergently (I just had to add that word to the web browser spell-check dictionary?!) or when getting students to do really anything.  I did require my students to first write down the “I notice” sentence and share that with the class.  Afterwards, they moved on to the “I wonder” and I required them to write something down first, which they then shared in small groups, along with how they attempted to answer the question through the simulator.

And yes, I realize that part of the problem may be that I’m trying to teach a Physics class using Modeling even though I’ve never had a workshop on it (this was strongly discouraged by a few other experienced teacher/modelers… oops).  I feel like I’m getting better each new unit I do, and my students are getting better at the same process, but talking in groups is essential for modeling, so I’ve got to figure out a way for them to talk more!

My Request

So how do you get your quiet classes to talk?  What other strategies or suggestions might you have to help me?  I’m really willing to try anything crazy (well, offering candy only goes so far with seniors…).

Oh, and why do I have #70, 80, 90, and 100 on the quiz, instead of #1, 2, 3, and 4?  See this post (original idea is from this guy.)

Filed under Teaching

## Make Students Show Their Work

All math & science teachers want their students to show their work, but so often students forget/are being lazy/think they don’t need to show their work, especially if they haven’t had a test in a long time.

Just Innocently Grading Quizzes One Weekend…

This weekend I was grading Chemistry tests, and was so frustrated at either (a) students not attempting problems when they know the first few steps, or (b) only writing down their answer to a very long and complicated problem (Stoichiometry).  So, I started class today with the following warm-up:

Students pointed out how “6th grader #1” got 1 wrong, but deserves the most credit because they showed the right mistakes, and so showed understanding whereas #2 deserves more credit than #3, even though #2 didn’t get very far on the problem.  I even went so far as to claim that #1, in some of my quizzes, and if they demonstrated an ability to do that correctly elsewhere, could still get a 100 because we all agreed #1 understood how to do the problem.

Of course, throughout this discussion, I still had the one or two smart-butts who were convinced that student #3 knew it the best (I’m 99% sure they were just joking), but I don’t think I convinced them to show their work because they “always” get it right (they really don’t…).

Easier to Talk about an Easier Problem

One thing that allowed us to have a discussion about understanding is that the math was easy enough for all the students (juniors in HS) to solve, so if you were trying to convince 6th graders to show their work, this might not be the first choice.  If I had chose a Stoichiometry problem (complicated Chemistry problem) to demonstrate “why you should show your work” then I think my students would have gotten lost in the mechanics of the problem and not seen the bigger picture.  Now, I hope that my students will not forget to show their work in the future.

How Do Get Your Students to Show their Work?

So I guess this took 5 minutes out of class in place of a warm-up (I had another warm-up after that one), so it did not take a lot of class time.  However, it helped tremendously that my students were used to my quizzes (which I think they recognize as testing understanding and not “how many you got right”), and it helped to have the discussion right on the  heels of a test where students can think about what they did wrong and learn from their mistakes.  Would this discussion have the same effect at the beginning of the year?  How do you convince your students that work is important?  Does it work?  Or is it a constant battle?

Filed under Teaching

## Failure Friday Fixed: A Better Logarithmic Application in Decibels

Here is my first success story from writing a “Failure Friday” post.  The “Failure Friday” idea is to give a lesson that failed and hopefully receive critical feedback on how to improve it, presumably for next year, although general suggestions could help one’s teaching throughout a year.  I am fortunate in that I teach 2 classes of Precalculus, one which is only a bit in front of the other in pacing, so I was able to use the suggestions and my improved lesson plan for the other Precal class.  Not only that, but my “failed” class, I was able to turn around and use the same lesson!

So the lesson is in this post if you care to read it.  The biggest problem that I had (even though I didn’t realize it at the time) was that I didn’t have a good way of visualizing loudness.  Thankfully, Kevin Laxton not only pointed this out for me, but also suggested the solution: Decibel Ultra on the iPads.  This was perfect because I have a class set of iPads, and I began brainstorming for a lab to do involving this app and students’ musical abilities (or lack thereof).

I started the with a very brief slide-show about sound.  Just enough to let them learn the basics, but not enough for them to lose interest yet.  Very soon after, I showed them the Decibel Ultra app.  All I did was hold it up.  My hope was that they would start yelling or slapping their desk in an attempt to make a loud enough sound.  What was funny was how self-conscious they became when they saw the meter move with their voice as they commented on it.

So I asked them an innocent question: “What different types of things could affect the decibel reader?”  They came up with the ones I was expecting, and a few neat other ones.  Included were distance to microphone, number of instruments/sources, pitch, as well as humidity, shape/size of room, number of other people in the room.  So I asked them if we could keep all of the variables the same except one of them (Oh, note: I did NOT use the word “variables”.  That’s one of those “Oh, you’re talking math, Mr. Newman, so I’m going to stop listening because it’s lame” words.  I said “things” and slipped in the word variables later when they were too into the project to notice.  Bwhahaha.).

Then I jumped into the hook and said “Okay, you guys are going to start a band!!”  You need a (1) Director (organizer and non-musical option), (2) “Sound Board” (Really just controls iPad and measure decibels), and (3) Musicians (really they could be slapping a stick on the ground to find decibels).

Here’s the powerpoint I went through with them during this.  Note: I did NOT show them the final slide, the one with the equations!! (It’s similar to my last slide with a few new edits).

After this, students broke up into groups, decided on a variable they were going to isolate and how they were going to “play” and measure the decibels.  Students had a blast going to different parts of the school (they couldn’t work in the same room as each other) and measuring their instruments.  Most of the data actually turned out really good!  Here are some pictures of them taking data:

When they came back together, the next day, I showed them Desmos (again) and modeled “playing with a log function” by adding, multiplying, etc. different parts of the function.  I was actually impressed with how quickly they found a function to fit their data once I released them to hunt on their own!  Here are some pictures of their graphs:

At the very end, I had the students find the real equation by doing some research on their own.  A few of the groups found really good equations, and one group found one that essentially matched their Desmos equation!! They were excited, and so was I for them. (It’s actually the 2nd graph above: you see their function was $y = 9.9 \log(x) + 70$ while they found $dB = 10 \log(x) + L_0$ so they did an incredible job collecting data and matching their graph in Desmos!

All, in all, I believe this was a much better lesson than the “application” worksheets I handed out a week ago.  True, there is not as much calculation here, but there is a lot more function manipulation, which connect to earlier in the course, so yay for that.  My next step on this subject: find a natural flow for that function manipulation.  And it may just have to be the worksheets, but we’ll see.

Thanks to Kevin and Tina for their help both in mentioning ideas and helping me to reflect!

1 Comment

Filed under Teaching

## Mousetrap Car Montage!

My physics students completed their “Mousetrap Car Lab” this past week, and I caught a lot of the final part on video and created a montage for them to watch. Enjoy!  (I’ll explain the lab below)

We are wrapping up our energy unit, and I had an idea for a challenge to my students: see if they can predict what angle a ramp should be so that their mousetrap cars would go up the ramp to the top, but not go over the ramp.  The students placed markers at the top to see if they could “knock it over” before they rolled back down.

My personal experiences of physics from when I was in HS was that almost no lab worked out, but you could always fudge the numbers to either (a) claim it worked or (b) explain why it didn’t and still get an A on the lab.  So I was a little worried this lab would be a complete flop.  To my surprise, it actually worked!

The downside to this lab was that there were so many different parts to it, that I had to hand-hold many of the students through the math (mind you, I’ve got students who are in Geometry all the way to Calculus as seniors, so quite the range).

Here are the steps (as clearly as I am able to put them):

1. Find the force of friction pushing back on the mousetrap car.  They did this by not setting the trap and letting the mousetrap car roll down a ramp.  They found the Gravitational Potential Energy and we assumed that friction was the only force doing work on the system.  We also assumed that friction was constant as long as the mousetrap car was moving, no matter what angle ramp it was moving on (a decent assumption, in my inexperienced Physics teacher opinion).
2. Find the Spring Potential Energy.  Once they know the force of friction, the students released the mousetrap car on a flat surface (ideally with a surface as similar to the ramp as possible) and used the two formulas for work to find the Spring Potential Energy because it is the only initial energy (final energy is 0 Joules).
3. Finally, they solve for what the Gravitational Potential Energy should be at the top of the ramp (before the car goes over) and use that height to find the angle at which the ramp should be set.

We spent a lot of time talking through the above steps, and I even had them complete a sample problem where I made up data for them to solve before starting the experiment.  I could improve this lab next year by taking the time to type these into lab instructions and providing more explanations for the students to read as they get to the steps.  Instead, I found myself going from group to group, re-drawing the same sketches and explaining the same thing over and over.  Good thing the class is fairly small.

The only group that was unsuccessful was because their “tires” (aka CDs) did not have enough friction, and they made all of their calculations with the wheels spinning out at the beginning of their trials (I guess they didn’t think that would matter??).  When it came time for them to go up a ramp, they did not have enough friction and the wheels just spun in place.  All the other groups, however, had very different angles on their ramps and came very close on several trials.  I was unable to videotape all the groups at once, and so I missed many of the successful trials.  Next year perhaps they’ll be required to videotape themselves and e-mail me the video.

Overall, I really enjoyed the lesson and I think the students did, too.  I was pleasantly surprised by how accurately the math came out, and will definitely be doing something like this next year!

PS–I made the video using OpenShot Video Editor, a free video editor for Linux, which is pretty sweet.

PPS–I have to thank Julie for her awesome video of the Barbee Bungie which inspired me to make the above video.  That, combined with the fact that our school just made class spirit music-videos had me thinking that I should use the video for a fun music video.

Filed under Teaching

## Failure Fridays: Logs and Decibels

Note: Thanks to Tina Cardone for setting up “Fail Friday” on Productive Struggle and helping share failed lessons like this so that other teachers can brainstorm for ways to help good intentions gone wrong, such as this one.

On Wednesday I started a lesson that I thought would be more engaging than “do these problems and keep going”… and the students complained MORE than usual!  Ugh, what a depressing day.

Well, now it is 2 days later, and I’ve had some time to reflect on what happened.  Let me explain what I did, and how I think I could have improved, although I would appreciate feedback as to more ways for me to improve.

The lesson was about Logarithms and came after my students had learned about how to solve for logarithms, and how to add, subtract, and multiply the logarithmic function.  I had actually created the lesson back in graduate school 3 years ago and was excited to actually get to use it (last year I forgot about this lesson).  In involves having students use the equation for decibels, which I provide below, and finding sound pressure (p) when given decibels (dB) and visa versa.

$dB = 10 \times \log ( \frac{p^2}{(2 \times 10^{-5})^2})$

I actually started the lesson by giving the students three areas of their lives where logarithms (and logarithmic scales) are used: earthquakes, magnitude of stars (you can see the stars really well out here in NM), and measuring sound volume.  I then allowed them to choose one of those three areas, and had them briefly research in class the following three points/questions:

1. Find one equation involving logarithms for the situation, and explain the variables in the equation.
2. Compare a few of the items on a scale and explain “how many times more” one of these things is than the other using the equation (e.g. “how many times brighter is Venus than the North Star and where do they fall on the scale?”)
3. Explain why logarithms (and a logarithmic scale) is used in this situation.

The students researched and presented, and all was smooth sailing up to this point.  Many of them were getting the point I was trying to make: that if you didn’t have a logarithmic scale, the numbers would be ridiculous to use and would be difficult to compare.  Instead, because scientists use a logarithmic scale, many people don’t understand when these are reported in the news (comparing a magnitude 4 earthquake to a magnitude 8 earthquake… the second one isn’t twice as big–it’s 10^4 times bigger!).

At this point, I decided to give “my presentation” on decibels (this was the least selected topic, and, in my opinion, one of the most interesting).

So as you can see above, I gave them the equations and showed a cool scale comparing decibels.  After this, I gave them the following worksheet (just pages 1 and 2) to fill out.

Note: I would NOT recommend stealing this worksheet without heavy editing!

Now note that this was my advanced Precalculus class, so I was trying to let them figure out the majority of this on their own–like Dan Meyer says “Be less helpful.”

Well, not only were students hopelessly lost, but they started complaining about the activity, which is rare for that class.  In my eyes, they were complaining about an activity which drew the math closer to the “real world” and gave purpose to what we were doing.  As one of the students commented “you guys always complain and ask ‘why are we doing this’ and this is why, and now you’re asking ‘why are we doing this?’ again??”

Well, I left the classroom rather discouraged and frustrated because I had expected a “better than average” lesson at worst, and was hoping that the students would really get into it, but instead I found a classroom of frustrated, tired, bored, and unengaged (is that being redundant?) students.

So what went wrong?

I want to start by think about something I read on a few people’s blogs, who had failed lessons and reflected on them.  The common theme between these was that the lesson was a great idea because it applied the content to the math very well, but it lacked a hook.

So I started looking for ways to improve that and I want to pause and quote a post from Dan Meyer’s blog:

Both of these things interested me, but the line from there to a classroom modeling task forces me to ask myself:

1. What question would lead to that interesting knowledge?
2. Is there some way I can provoke that question visually?
3. Could a student guess at that question?
4. What information would a student need to answer that question?
5. What mathematical tools would a student need to answer that question?
6. Is there some way to confirm the answer visually?

So the next time you see something that’s simultaneously a) interesting to you and b) mathematical, try running through those questions above and see how they’d play out. In the meantime, you can check out my specific answers above.

Those are all very, very important questions if you are designing a lesson for students to be engaged and interested because you think the topic is interesting.  As Evan Weinberg said:

I need to be a lot more aware of the level of my own excitement around activity in comparison to that of the students.

So how can I improve the hook in this particular lesson?

Well, for starters, I could not start by giving them the equation.  Could they find the equation above simply given a list of sounds, their respective sound pressures and decibel levels?  Possibly and possibly not, but now we’ll never know.  Either way, they would have a much more intuitive grasp of what the equation means.  Instead, I found myself explaining the equation and the parts of the equation several times over–I probably wasted more time than I would have if they had struggled with it!

This lesson also enlightened me to a difference between good struggling and bad struggling, which I previously did not know existed.  Students struggling to find “the right place to plug in the number you gave them into the equation you gave them” is not good struggling.  Students working to find a relationship between numbers and working to have a rigorous conversation about it is better.  Students struggling to see what that relationship means and how they can use that relationship for future problems is even better.

I thought I had I created a pretty neat extension activity, if I can just find the right hook and present it better (this class is still working their way through this worksheet) I might have a chance to redeem this activity for the students and for myself.  As for answering Dan’s questions above, no, I do not think there is an easy way to verify this visually.  If the students were elite musicians, I could possibly verify our finds through experiments and having the students bring their instruments into class.  Even with speakers, I’m not sure students (nor I) could hear the differences in decibels acutely enough to know whether our calculations were correct.

I will also not discount the effect of students’ lives into the situation.  I spoke with one particularly frustrated student later and found out that this student was having a “bad 3 days outside of class”, for which she and I apologized to each other for our respective lack of thoughtfulness.  You can never discount the baggage that many students bring to your room on a daily basis.  However, I will not use that as an excuse not to improve this lesson which clearly could have been better handled.

Please let me know if you have a better idea on this lesson or if you have a better idea for a lesson plan using logarithms (I suppose I haven’t had time to search many sources for one of these).