categories - same/different

Categories seem to give my kiddos are hard time... the concepts of "same" and "different" do too...  So here's a technique I used today with my 4th graders that seemed to help a lot:
1.  I had the kids color and cut out pictures that belonged in the same category.
2.  After they cut and grouped the pictures, I had them turn the card over and write out the name of the category.
3.  Then I said, "see how they are all the same?  They are in the same category.  Now flip them over.  Let's talk about what's different."

A light bulb came on!  I love "ah-ha" moments!