by C. Elkins

I have heard from a few 4^th grade teachers that a new standard is difficult for their students to grasp. It is 4.GM.2.2: Find the area of polygons that can be decomposed into rectangles.

I have a couple of suggestions which help students with a concrete-pictorial-abstract progression approach to this problem (which is more developmentally appropriate).

1. I have attached an activity which involves the use of 1” color tiles to partition off irregular shapes and then determine the area of each smaller rectangle. It’s free and in 2 parts:
   • Directions and example pictures: Using Color Tiles directions
   • Forms for students to use (labeled A-E), plus extra blank 1” grid and cm paper:  Using color files forms
2. I located an excellent reference which shows pictorially how to do this step-by-step. It also includes good information about perimeter. It is:  Area and Perimeter

Some troubleshooting tips:  Continue reading →