Here in North Carolina, it starts in 9th grade. Elementary is Kindergarten to 5th, Middle School is 6th to 8th, and High School is 9th to 12th.
In some states, Elementary is K-6, Junior High is 7-9, and High is 19-12.
Yep, that is a much better system.
Infant= 1,2 (age, 5,6)
Primary= 3-6 (7-10)
Secondary (HS)= 7-11 (11-15)
Is just daft.