Friday, January 3, 2014

Building Number Sense

My first post explained how we are using estimation180 in our grade 4 classrooms.  We have two sections; the students in one are keeping track using the hand-out provided on the site (with some age-appropriate modifications). The students in the other section are now placing their "too low", "too high", and "just right" predictions on an open number line, and then placing the correct answer accordingly.

 Here's an example:

This is from the clementine prompt.

Asking kids to place their estimates on a number line has led to all kinds of interesting issues and discussions.  Students naturally want to place their "just right" prediction halfway between the "too low" and the "too high", and they are getting better at figuring out where that is as they scale the number line. Fractions and decimals are providing another challenge, especially with the measurement activities, where, for example, 4 ft 5 inches is not 4 1/2 ft!
   It's clearly a work in progress, and we need to continually reflect on what we are doing and where we are going.  I owe a debt of gratitude to my colleagues, who have been willing to experiment and engage in reflection as we try to make math more meaningful for our students.


  1. Hi Joe! I LOVE the idea of putting their high/low/just right on the number line. What a great way to incorporate this important concept into estimation! One year I had an 8th grader show me that 4/5 was between 4 and 5. Oy. Thank you for sharing, Joe.

  2. Thanks for your encouragement Fawn. As you were one of the inspirations for this blog, that means a lot to me. I hope I can add my voice to those others who are working to change the dynamics of what happens in math class.

  3. Joe, I'm so glad that Fawn sent me the link to this post. I think it's a fantastic idea to add the use of a number line when defining the range of possible answers along with the correct placement of the "just right" predictions. I dig it! A LOT!
    You couldn't have said it better, "It's clearly a work in progress, and we need to continually reflect on what we are doing and where we are going."
    This truly is a work in progress. They do get better and it's amazing to think where they were when they first started these estimation challenges.
    Keep up the great work!

  4. Thanks Andrew, and thanks for the shout out on your blog. When I came across the estimation180 site last year, I knew immediately it was something we had to incorporate into our classrooms. I needed some teachers willing to give it a try, and have faith that the time and effort would pay dividends. I was fortunate to find them in my fourth grade team.