Living in Southern California, the grade school I attended for Kindergarten and on up was built the year I attended. In its first year, I distinctly remember having 6th grade in our school, but not when I entered 1st grade.
I also attended Preschool in a little, green and white schoolhouse in town. I wish I could find info on that dangnabbity schoolhouse, because it was apparently an older building, not unsafe in any regards, but it DID lack electricity. I could still grab photos, though its now boarded up, and sits in a parking lot not far from where it was formally located.
Back on topic, we called it Elementary, then either Junior High OR Middle School (this might have to due with heavy culture influx from both the midwest and the LA areas, both), and High School. When I did my run, it was Pre, K-5, 6-8, then 9-12.