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Tuesday, January 8, 2013

Distributive Property Mania!!!!!

We have been working for WEEKS (I'm not exaggerating) on area and perimeter, and now we are throwing in the distributive property just for fun to help explain how to find the area of rectilinear figures.

        3.MD7c Use tiling to show in a concrete case that the area of a rectangle with whole-number     side lengths a and b + c is the sum of a × b and a × c. Use area models to represent the distributive  property in mathematical reasoning.

I am discovering (as are the math teachers in most of the states in America) that the Common Core standards are MUCH more complicated than they look on paper.  We were warned, right?  Now I'm a believer! 

ANYWAY, we have done a ton of activities to become more familiar with the distributive property.

First, we used this lesson on the distributive property where students used Fruit Loops to create arrays.  I began introducing problems like 4 (3 x 4) and we made arrays to correlate with each of the distributed facts.


 After practicing (and munching) through several examples, we used pre-cut  1-inch squares to create arrays.  We went through the Break-Apart Arrays activity where students created all of the possible ways to break an array for 12 (we did 2 x 6).  The possible break-apart arrays included
                                                         (2 x 1) + (2 x 5)
                                                         (2 x 2) + (2 x 4)
                                                         (2 x 3) + (2 x 3)
                                                         (2 x 4) + (2 x 2)
                                                         (2 x 5) + (2 x 1)
We also split the array horizontally into (1 x 6) + (1 x 6).
Students wrote down all of these arrangements on a recording sheet.
 The students worked independently to record all of the possible break-apart arrays for two other products.  It definitely got easier the more that students practiced it!
Finally, students chose one of their arrangements to glue onto a piece of construction paper.  We again went through the process of writing equations with the distributive property.
                                                   4 (2 + 4) = (4 x 2) + (4 x 4)
We are continuing to work on the distributive property, but without the manipulatives.  It is definitely challenging, but I am hoping that all of our practice will make a difference in their understanding of this important property of multiplication!

2 comments:

Co-Kindering said...

I teach K, but love to teach addition and subtraction with cereal or food! It works so well! So glad that I found your blog- would love for you to stop by mine:)

Julie Goode said...

What a fun way to practice! Thanks for sharing!
-Julie
The Techie Teacher

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