Thursday, March 20, 2014

Math Lit: The Greedy Triangle

This week's math lit post is about another great geometry book, The Greedy Triangle by Marilyn Burns.

From Amazon: Bored and dissatisfied with his life, a triangle visits a local shapeshifter to add another angle to his shape. Poof! He becomes a quadrilateral. But then he gets greedy and keeps adding angles until he's completely transformed.

Students seem to always enjoy this book when I read it, and this year I had a little something special to add. Thanks to a Math Solutions training, I learned how to make a shapeshifter for them to manipulate during the story!

All you need is 4 inch squares of construction paper. Fold in half to make a rectangle, then again to make a small square. Unfold, and fold in half diagonally both ways. Then fold the corners to the middle (the students know how to do this from making fortune tellers). 

As you read the story, manipulate the opened square to make: triangle, quadrilateral, pentagon, and hexagon! I like giving the kids a chance to try to come up with the shape on their own.

We had so much fun telling the story with our shapeshifters! 


  1. This is such a fun book! One of the third grade teachers at my school does the Reader's Theater of this for my class every year. It's so cute!

    Sara :)
    The Colorful Apple

    1. I LOVE that idea. I think I will develop a Reader's Theater for the book so my kids can do it.

  2. Thanks for the wonderful idea. I think I know what I am going to do for my upcoming formal evaluation!

    1. Geometry is great for evals, because there are so many fun things that engage students while learning. I was doing a geometry lesson last year when I had my formal.

  3. An iOS app you may be interested in is MathCrunch, which lets you take a picture of your tough homework problem, send it to a live tutor, who solves it on the spot and walks you through the working steps.


Pin It button on image hover