Here is an article that addresses the some of the main reasons why dividing children by age in traditional schooling systems does not make sense. When I was a public school teacher there were many things that I did not question at first, and this was one. Even though I knew there was something wrong, tradition is strong in the area of education these days. But just because something has always (or seems to have always) been done a certain way, does not mean things have to continue that way. I had the fortune of being an orchestra teacher, where, although my individual classes were divided by age, the performing group was a combination of grade levels. Primarily 6th – 8th grade. On occasion though, I could invite a 5th grader from the elementary program, or even a 4th grader who was ready, to perform with the middle school orchestra. Proof that age was not a true indicator of ability. Not to say that younger is better or smarter, just in the area of music performance, there were many levels of ability spread out among several age groups. Many 8th graders would have been happier playing and learning the music I gave to my 4th graders, because of the age they started, or their interest level in learning the instrument – a variety of reasons. And many 4th graders were thrilled to be playing in an ensemble performing music of their ability level, which happened to be music that my 7th and 8th graders were playing. It’s simple. Learning does not happen according to an age chart. So, why would you design your classroom that way?