Thursday, April 18, 2013

More Tangrams Please!

This week in Geometry, we did the 3 Act lesson Hedge Trimmer. I'll debrief about that another time. Students needed to find the area of some isosceles trapezoids along the way and I didn't give them access to the area formula for trapezoids. Instead they needed to be resourceful and figure it out on their own. Well, that didn't go too well at first [cue the whining]. Many students had trouble breaking the trapezoid into 3 polygons: a rectangle and two triangles. Their warm-up the next day was to play around with tangrams for the first 5-10 minutes of class.
Me: Use all seven pieces to make any one of the following polygons. Do your best!
I drew a square, rectangle, trapezoid, parallelogram, triangle, and circle. I'm just kidding about the circle. However, I should have drawn one. That's funny. My 8th grade students were terrible at this. I use "terrible" with all the love in the world, knowing this is a learning experience for them.
Me: Have you guys ever messed around with tangrams?
Class: No!
Me: WHAT!!!! Are you guys serious? No one has ever let you mess around with tangrams before? Well, I'm glad we're doing it now. You guys need this. Seriously? You guys have never messed around with tangrams.
Class: Nope.
Me: Okay, well keep trying. [as I began scraping my jaw off the floor]
My request to you all: MORE TANGRAMS PLEASE!

Especially elementary teachers, more tangrams please. Have your students mess around with them. Sure you can download some app onto your tablet or find a web-based site to simulate tangrams, but please do your best to get actual tangrams into the hands of your students. Math formulas come and go for math students. However, if they can visually break apart polygons into more recognizable polygons such as rectangles and triangles, I believe their mathematical proficiency greatly increases. My goal is to get these 8th graders to play around with Tangrams once a week for the rest of the year. At least one of my students was eventually able to put together a trapezoid (top left), which quickly turned into a parallelogram, which quickly turned into a rectangle.
Me: How'd those other shapes come so quickly?
Sean: I just moved this one larger triangle to different spots.
I took a picture of his first configuration so I could share it with the class. I figured I'd give the class a chance to redeem themselves and copy his rectangle configuration.
More tangrams please! 
Repeat after me:

Thanks for listening.


BTW: Cheat sheet for displaying student work immediately:

  1. Sign up for Dropbox.
  2. Have the Dropbox app on your phone.
  3. Take picture(s) of student work.
  4. Allow the app to upload your camera photos.
  5. Sync your computer with Dropbox.
  6. The pictures arrive on your computer in seconds.



  1. It's not quite tangrams, but here's our latest shapes question:

  2. My jaw is isn't dropping, it is making a frowny face because now I feel sad. It makes me sad that some kids never get to play with Tangrams. (I am sure there is hopefully someone out there who is saying, geez, your kid never got to milk a cow, really?)

    Great reminder, thanks. Don't forget to debrief us on the Hedge Trimmer 3 Act...surface area vs. time? I am thinking about using that almost 5 minuter in my punishment room with the Bay City Rollers and Captain and Tenille! (Sorry I don't know how to tweet yet, maybe that is more appro, pro there!).

    Love the Pictures as always. Amy

    1. Thanks Amy!
      It is sad to think some kids never get to play with Tangrams. I was one of those kids. Love the cow reference, ha! I'll hopefully get around to some notes on Hedge Trimmer. Thanks for checking in!

  3. Thanks for the post. I agree - tangram exploration is a must. I've used them with K-12 students and have found that giving students a paper square and letting them fold/cut their own set of tangrams is a great way to introduce them to the shapes. Lots of opportunities for discussion along the way.

    Make Your Own Tangrams