## Tuesday, December 13, 2011

### Multiplication Unit

Multiplication Unit

My multiplication unit begins with a review of arrays.

I love my magnetic

whiteboard!

Large Arrays
 Before my students begin modeling their own large arrays, we spend a couple of days creating arrays using pre-made templates from AIMS Marvelous Multiplication and Dazzling Division book. Students position base ten blocks to visualize the process of multiplication.
I copied and laminated enough of these templates for each student in my classroom, and placed them in manilla file folders.  I also placed base ten blocks in plastic baggies.  This makes it simple to quickly hand out the materials and get started on the activity.

My students enjoy creating their own large arrays.

Here are a few of our large arrays.  My students label each section of the array.  When they are finished with the large array, the children use the distributive property to check their answers at the bottom.

"The Properties"
Commutative, Associative, and Distributive properties of multiplication.

My students created
their own designs to
model the
Commutative
and
Associative Properties

I thought this design for
the Associative Property
was very creative.
It's hard to believe that a 9 yr. old
can draw this well, but, she can!

I am particularly fond of the football jersey models of the properties. My son is the kicker for our high school football team and his number is 5.  This child always goes to the football games and the other 2 numbers he is modeling are our 2 of our team's starters...one of which is his cousin.  I think this is a good example of using prior knowledge to problem-solve :)

Multiplication Grids

When my class gets to larger multiplication problems, I use a grid that I purchased from a school supply store years and years ago. I placed magnets on the back of the grid to use on my magnetic whiteboard.

I begin by placing a post-it note on the digit on the second row that is not being multiplied.  Then I switch the post-it to the other digit and multiply.
This way the students do not become confused.

My students model the large grid by using
grid paper at their desks.  (This centimeter grid paper is large enough to write a digit in each square.)  The grid paper guides students to place the digits in the correct columns and keep them aligned correctly.
I have my students cut out a single centimeter square at the bottom of the grid to cover the digits not being used on their own grid paper.  (I have shaded in the centimeter square so you can see it on the picture above.)

Birds of a Feather
This is a 2 x 2 digit multiplication activity.  It takes a while for the students to finish.  First, the students work out 24 problems on notebook paper, then transfer the answers to the Birds of a Feather handout.  Finally, the
they cut and paste the birds onto the handout.  The directions tell which birds go with which numbers.

As you can tell by the notebook paper laying on the corner of the desk, there is a lot of work involved with this multiplication activity.