What is the average number of children in a containment classroom?

I believe the answer would vary depending on the age and grade level of the class, as well as where you teach, but based on my experience as the parent of a special needs child (and also the parent of a neurotypical child), the inclusion class size is larger with a higher student to teacher/paraeducator ratio. From the class sizes I have seen in my county (in Maryland), inclusion classes are about 20-24 kids with only 1-2 paraeducators or teacher's aides (if any), whereas containment classes have anywhere from 6-20 kids, and usually 3-4 paraeducators and/or teacher's aides. Again, it can vary greatly depending on the school district and age/grade level. It's a very tough but rewarding job, and I owe a lifetime of gratitude to each and every one of my son's teachers who have been instrumental in his learning and development. Best of luck to you!