Well, I don't know exactly what "prom" means for you then, because if it means something else, then I may be mistaken.

What does 2 years Alevel mean? O _ O

Also, for us, elementary is usually kindergarten - 5th grade (so that is 6 years I believe) and then we go to middle school which is (6th - 8th grade) so that's 3 years. And then 4 years in high school up to 12th grade, graduate and go to 4 years of college.