Synergizing

As a part of math every day, we do what we call "Happy Counting!" where we practice skip counting and working our way from one number to another.  Lately, we've been talking about using the "most efficient units" to move between numbers and today we put that into practice as we moved from 40 to 470.  The students suggested a couple different ways to move between the numbers.  Caleb suggested we start counting by tens until we reach 170 and then we switch to count by hundreds until we reach our target number of 470.  Vanessa Ann agreed that we should start by using units of ten, but thought we should switch at 100, since it is a benchmark number.  She suggested counting by hundreds until 400, and then switching back to units of ten until we reached 470.  In either case, we found out that we were going to use 3 hundreds and 13 tens to reach our target number.

What baffled the class, however was that 300 + 130 = 430.  Wasn't our target number 470?!

We thought...

...and thought...

...and thought.

Then we SYNERGIZED!!

The class quickly grouped itself and kids began sharing ideas.  We reminded each other to "Seek First to Understand (Habit #5) and then to be understood!  

Students grabbed scratch paper and drew their math ideas!

We had lots of different approaches.

Students even used the "Win-Win" (Habit #4) to make sure everyone participated!

No matter what we did, though, we kept coming up with 430 as our answer.  Why weren't we coming up with 470?

This is what SYNERGIZING looks like!!  (It was a really cool moment!)

It took awhile, but Vanessa Ann finally led the class through an explanation of why the "answer" was 430 and not 470!  It all depends on where you start!