<P> In the U.S., ordinal numbers (e.g., first grade) are used for identifying grades . Typical ages and grade groupings in contemporary, public and private schools may be found through the U.S. Department of Education . Generally there are three stages: elementary school (K--5th / 6th grade), middle school (6th / 7th--8th grades) and high school (9th--12th grades). </P> <P> There is considerable variability in the exact arrangement of grades, as the following table indicates . </P> <Table> <Tr> <Th_colspan="4"> General level (or category) </Th> <Th> Level </Th> <Th> Student age range (at the beginning of academic year) </Th> </Tr> <Tr> <Td_colspan="4"> Preschool </Td> <Td> Pre-kindergarten </Td> <Td> 3--5 </Td> </Tr> <Tr> <Th_colspan="6"> Compulsory education </Th> </Tr> <Tr> <Td_colspan="4"> Elementary school </Td> <Td> Kindergarten </Td> <Td> 5--6 </Td> </Tr> <Tr> <Td> 1st grade </Td> <Td> 6--7 </Td> </Tr> <Tr> <Td> 2nd grade </Td> <Td> 7--8 </Td> </Tr> <Tr> <Td> 3rd grade </Td> <Td> 8--9 </Td> </Tr> <Tr> <Td> 4th grade </Td> <Td> 9--10 </Td> </Tr> <Tr> <Td> </Td> <Td> </Td> <Td_colspan="2"> </Td> <Td> 5th grade </Td> <Td> 10--11 </Td> </Tr> <Tr> <Td_colspan="2"> Middle school </Td> <Td> </Td> <Td> </Td> <Td> 6th grade </Td> <Td> 11--12 </Td> </Tr> <Tr> <Td_colspan="2"> Junior high school </Td> <Td> 7th grade </Td> <Td> 12--13 </Td> </Tr> <Tr> <Td> 8th grade </Td> <Td> 13--14 </Td> </Tr> <Tr> <Td_colspan="2"> High school </Td> <Td_colspan="2"> </Td> <Td> Freshman / 9th grade </Td> <Td> 14--15 </Td> </Tr> <Tr> <Td_colspan="2"> Senior high school </Td> <Td> Sophomore / 10th grade </Td> <Td> 15--16 </Td> </Tr> <Tr> <Td> Junior / 11th grade </Td> <Td> 16--17 </Td> </Tr> <Tr> <Td> Senior / 12th grade </Td> <Td> 17--18 </Td> </Tr> <Tr> <Th_colspan="6"> Higher education </Th> </Tr> <Tr> <Td_colspan="2"> College (University) </Td> <Td_colspan="2"> Undergraduate school </Td> <Td> First year: "Freshman year" </Td> <Td> 18--19 </Td> </Tr> <Tr> <Td> Second year: "Sophomore year" </Td> <Td> 19--20 </Td> </Tr> <Tr> <Td> Third year: "Junior year" </Td> <Td> 20--21 </Td> </Tr> <Tr> <Td> Fourth year: "Senior year" </Td> <Td> 21--22 </Td> </Tr> <Tr> <Td_colspan="5"> Graduate school (with various degrees and curricular partitions thereof) </Td> <Td> Ages vary </Td> </Tr> <Tr> <Th_colspan="6"> Continuing education </Th> </Tr> <Tr> <Td_colspan="5"> Vocational school </Td> <Td> Ages vary </Td> </Tr> <Tr> <Td_colspan="5"> Adult education </Td> </Tr> </Table> <Tr> <Th_colspan="4"> General level (or category) </Th> <Th> Level </Th> <Th> Student age range (at the beginning of academic year) </Th> </Tr>

At what age do you start high school