## 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.