Algebra Technology

What to do Before a Hurricaine

Perhaps the best part of my job as math coach is working with teachers of various grade levels on lessons; developing “hooks” for discussion and inquiry, and being invited into classroom to share exciting stuff.  It’s a neat feeling to have kids say hello in the hallway, and ask when I will be around to visit their class again.  This week, final exams are being held at out high school, which means that new courses begin next week.  This presents a great opportunity to challenge teachers to think differently about how they start off with their classes.  How can review of previous material be done in a way to both allow for a discussion of previously-covered concepts, but also set the table for a class culture of productive idea-sharing?

Dan Meyer’s blog, has been a great source of inspiration to me, and I shared his TED talk with my district’s secondary math staff at an inservice this year.  The talk led to an interesting discussion about the questions we ask in the classroom, and healthy debate on how we can re-think lines of questioning.  And while Dan is an advocate for all sorts of useful and productive classroom technology integration, what I appreciate most are his self-made videos and demonstrations.  One of the simplest, yet effective, videos shows a hexagonal tank being filled with water, then later emptied.  The video leads to the natural question “how long will it take for the tank to fill”, and leads to all sorts of nice math ideas like linear growth, prediction, and error.

Being a brave soul with decent, but hardly expert, tech skills, I set out to do a video on my own, in order to inspire my colleagues.  Sure, I could have just used Dan’s videos, but the “what the heck is he doing out there?” look from my neighbors is just too much to pass up.  Besaides, the “anyone can do this” factor is strong here.  Find neat stuff in your environment, and go with it.  So, with a jug from Wal-Mart, some cherry juice mix, a laptop, and my home camera (nothing too fancy), I set out in my backyard hours before hurricaine Irene.  I tried my best to emulate the best of Dan Meyer, but with my own flavor:

I first used this video as an ice-breaker in the in-service days before school, in July. Stopping the video a minute in, I asked math staff to predict how long it would take for the tank to empty, using the neat site to have teachers contribute answers via cell phone.  (To be honest, this worked well at our high school, but was problematic at our middle school, where wireless connection gremlins tripped me up).

So, how to use this as an opener for a course, perhaps Algebra II?  I found today that if the video is shown on a whiteboard, then drawing a vertical guideline on the side of the jug and placing tic marks can allow for some nice data collection as the water level decreases.  Importing the video into a SMART notebook could allow for a nice scale to be drawn on the jug.  Either I’d like to find a way to super-impose a line on the video, or I may go the low-tech route and place tape on the side of the jug and reshoot.

What directions can a discussion of this video take?

  • Independent vs Dependent variables (is the water level dependent on the time, or vice versa?)
  • Differentiating linear and non-linear models
  • Using technology to analyze data and develop regression models
  • Making predictions based on models

Any other thoughts or ideas?


By Bob Lochel

HS Math Teacher. Hatboro-Horsham School District, Horsham, PA.

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