Showing posts with label Subtraction. Show all posts
Showing posts with label Subtraction. Show all posts

Friday, January 18, 2013

Subtraction Jingle

So of course, by this point, my students have figured out that it is much easier to use the splitting method for subtraction.  However, they know that we are using this method when there is no regrouping involved:

   4 6
 - 2 3
   2 3

4 tens - 2 tens = 2 tens           
6 ones - 3 ones = 3 ones

When there is regrouping involved, we still like to use an open number line.  In order to remember when to use which method, we have this little jingle going in the classroom... Click on the pic for the link.  Of course, in true 2nd grade fashion, the kids made up some groovy dance moves to go along with the jingle.  In fact, that was part of the fun - each table came up with their own dance and hand gestures to remember the jingle.  Whatever works :)

Grab it here:


Freebie Fridays

Sunday, January 6, 2013

Deep Sea Dive to Zero Open Number Line Subtraction Freebie

Classroom Freebies Manic Monday

Boy, did we have fun in math on Friday! With all of our addition strategies under our belts, we've been working on subtracting.  I have to say, the Common Core focus on Numbers and Operations in Base 10 has really helped with addition and subtraction both with and without regrouping.

My students are practicing their facts through games every day during Guided Math.  They play these games "in the workshop."  To review addition facts, they are still having a blast with my Math Facts Superheroes Games.


However...they have also been really enjoying some wonderful subtraction games I bought from Fun Games 4 Learning:
Getting back to Friday... We are focusing on splitting numbers into tens and ones to subtract.  This is a strategy I find very helpful for the kids.  Many of the strategies that I am using come from Marilyn Burns: Do The Math.  It's a GREAT resource for teaching addition and subtraction strategies!
I made a game based on how Marilyn uses splitting tens and ones on an open number line to subtract.  I played this game with the whole class. 
 That's right, it was me against all of them- and they LOVED it! Each child had a game board, a die and an Expo marker.  I took a turn and explained my thinking of whether I should subtract tens or ones to get closest to zero.  Then the kids all took their turn at the same time.  After each roll, we announced who was "closest to zero" at that point.  The game is only 6 rolls long, but it is pretty intense - you cannot go under zero before your 6 rolls are up or else you lose a turn.  The person closest to zero at the end of the game is the Deep Sea Diving Champion!

When it was time for me to pull groups for Guided Math, the kids who remained in the workshop all chose to play this game again.  It was a winner,  and I am giving it to you for free.  Enjoy!