## Monday, February 10, 2014

### Math Is Real Life: 100s Day Computation Challenge Game Board Design

Today I was inspired to join Miss Math Dork in her Math Is Real Life series!  Although this math problem is for school, it is a real life teacher problem, so I think that qualifies. :)

My task was to create not one, but two posters this year for our 100s Day of School math competition.  Although I posted about this last year over at Shut the Door and Teach, this year Mr. E next door wanted his class to join in on the fun.  This time there would be 2 fourth grade classes competing to solve 100 2 digit by 2 digit multiplication problems.

Therefore, my first task was simple enough.  I needed to find half so I divided by 2.

The next task was a little more complex, and exactly the sort of problem that I've asked my fourth graders to find.  We had decided to be the "Red Team" and the "Blue Team," and I had 2 18" x 24" poster boards in red and blue.  The math questions I had were:
• Are the posters big enough for 50 Post Its each?
• Which area model will work best for my Post Its?
I started out with 3 different area models.  At first I thought 5x10 would be the wrong dimensions for a typical poster board, until I remembered I would want a title.

I love that my models represent what to do with remainders!  They are not just an afterthought; they are important too!

I also love that B and C turned out to be the same, just with a different layout.  Therefore I only had to carry on with two options as I continued.

My next math problem is that each sticky note is 3" by 3."  Therefore I had to multiply the length and width of each row and column by 3.

Seems straightforward, however when thinking about the real world application, a poster requires a bit of "wiggle room."  Practically speaking, I need about 1/4" of space in between each sticky note if we're going to be taking them down and putting them back up again.  That means that after the first 4 rows/columns, I need another inch.  For the 5th through 8th row, I need a second inch, and so on.

(Just noticed a misspelling on one of the "columns," sorry).  Notice that labels became important here!  I admit, when I was writing this out I originally added on to the inches, not to the rows/columns, but I quickly realized my numbers were way too large.  By labeling columns, rows, and inches, I was able to keep track of where to add the extra few inches.

The result:  Sadly, my 18" by 24" poster board was NOT going to work for this project.  Luckily, in true teacher fashion, I had spare chart paper that was plenty large enough.  Here are the results:

A little planning and math know-how saved me from having to redo at least one poster!  Now they're ready for Thursday (weather permitting).  I can't wait to show them off to the fourth graders.

If you have a Math Is Real Life story, why not join Miss Math Dork's linky?
A monthly REAL WORLD

And if you'd like to read up on last year's 100s Day festivities with my fourth graders, you can catch it here at Shut the Door and Teach