A Game, a Decimal Point, and Some Formative Assessment

    Looking for a fun way to have the fifth graders practice their multiplication and addition facts, I mashed up two games, one from Math 4 Love and the other from Malke Rosenfeld.  I did a demo round, then wrote the rules on a whiteboard:

Fact practice, division, some strategy: what's not to love? 

I hoped they could come up with something creative.  In the interim we called it, "The Game With No Name".

The entries came in fast and furious. 

     As I walked into class one afternoon, a little later than usual, I sensed something wasn't right.  The room, normally buzzing with activity, was quiet, save for the sound of suppressed giggles.
    "Something going on I need to know about?" I asked.
     Rich looked at me with a smile.
    "Check the whiteboard."

Look carefully.  I missed it at first glance, too.  Someone had erased the decimal point.

;
     "Oh no!" I cried out, in my best fake-horrified voice.  "How in the world am I going to come up with that kind of money?  I've got bills to pay!  A family to support!"  I turned to Rich, pleading,
     "Maybe Mr. Whalen can help me out?!"
     They couldn't hold it in any longer.  The class exploded with laughter.  It took a few minutes for them to get back on task, but I didn't mind in the least.
    "Well," I said, turning to Rich, "There's a little bit of formative assessment for you.  Someone in here knows the significance of a decimal point."
     And the winner was...

Second place: "Alligators on a Train: Math Edition".  Don't ask.