I am part of a team of 6 volunteers who teach sewing and quilting to anyone 9 years old to adult. After three years, we have found that even 8 year olds have a very short attention span. Our participants start with a potholder with one side a 16 patch and the other a 4 patch. This lets them understand how even seams lead them to two same-sized pieces.
Good Luck with your teaching. Please share the results after your class.