## Friday, March 7, 2014

### Opening Pandora's Box

Because decimals can be confusing when you're nine years old, and because we like number lines and estimation180-like activities, and because we live in a world where 4.NF.C.6 exists, Jeff, Shannon, Theresa, and I decided to try something a little different with the fourth graders last week.

Day 1
We decided that, instead of having the kids make their own number lines, we would give them one that was pre-made:

 They were told that the amount was between \$0.00 and \$3.00.  We had them place their "just right" estimate, and then the actual total, on their number lines.  Instead of using a new one for each day of the series, they would use just this one.  I liked the idea of having the one number line fill up with decimals.
 We made them count the money instead of simply revealing the answer.

Day 2

Day 3

Day 4

Here's a sample number line after we were finished:

This is all very interesting to us, because as we explore more of these activities we get deeper into number sense than we ever have before and, developmentally, the kids are all over the place.

Yesterday we went back to our first activity:

 How tall is Mr. Stadel?
Except this time we wanted them to estimate his height in meters.

 Jeff's AM class.

 Jeff's PM class.  Over lunch it occurred to me that a vertical number line might provide a better visual for height estimates.
When we made the decision to replace our traditional "math message" with a daily estimation-180 activity, we never imagined it would lead to places like this.  It seems as if we've opened up something of a Pandora's Box (where good things fly out?)  But it's too late now to close it, and who knows what else is in there?