## Wednesday, February 27, 2013

### Computation Challenge: 2 Digit Multiplication (How To)

It seems like 2 digit by 2 digit multiplication is one of those procedures that kids HATE.  And STRUGGLE with.  And need tons of PRACTICE to master.  The question is, how do you get your fourth graders to sit down and practice all those steps enough times to really internalize them instead of raise their hand to go to the bathroom or get a drink of water, only to vanish for half of math time?

The answer: the 100s day computation challenge.  It can be done any time of year, but I thought it up on the 98th day of school this year, so I rolled it out on 100s day.  And it was a hit!

Step 1:  Set Up

I stuck 100 Post Its to our portable white board, then wrote the problems.  The thing is, my class is at the point where they really need to drill down on their 6, 7, 8, and 9s, not the easier facts.  So this time around, I was sure to get some 9s and 8s in each problem.  If I do an encore of this activity, you can bet it will feature 6s and 7s.

Step 2:   Foster Collaboration, Not Just Competition

I know that competition is healthy, but I believe it's healthy in small doses.  More important in a classroom setting is to foster social skills and teamwork.  So here's how I did it:  As usual, I gave my kids a "test" consisting of a single problem to determine who needs help, and who could give help.  They were allowed to use any method they want (my Multiplication by Color Task Cards were a great way to practice the standard algorithm).  I lined them up in two rows.  Then I alternated red and blue wristlets (stapled construction paper) so that the ability level of each team was even.  I let them know that if they "need help," they should check in with someone on their team who is a "helper" before bringing a problem up to me to be checked.  I also let them know that "helpers" should be sure to not only complete their own problems; they need to watch for their teammates who are looking for help with a step.

This was a hard lesson for SO many kids!  That's why I mentioned doing an encore above.  Not only do they need to practice their 6s and 7s, many of them had to find out for themselves that ignoring struggling teammates in order to do as many as they can on their own was not the way to go.  But more on that later.  At least some of the kids got this.  I had two students tell me during the course of the game that one of their peers is a good teacher.  "I needed help, but I don't anymore because she taught me how to do it.  I don't need to be checked now."  Huzzah!

Step 3:  Game-play and Management

To help with the pacing, that is, to prevent them from rushing in and grabbing the easy ones first, I drew a box around a big chunk of those problems in the top left corner.  I told them that they had to finish the problems in the box first, before moving on to the rest (this way those easy problems on the right and bottom edge were only accessible in the middle of the game, as a bit of an unexpected break).  I also pulled names to fairly decide who got to choose a problem first, second, third, and so on.  I had the two teams sit in different areas of the room as they worked, and then come over to me (sitting near the game board with a calculator in hand) to get in line and get their work checked.  If a student got the problem right, I colored the corner with their team color, and he/she got to stick it back up on the board.  If they got it wrong, they were required to hand the problem over to a member of the opposing team.

Tomorrow I'll let you know how it all went down!