removing group by clause with SUM
Take your most complex (most GROUP BY columns) then use the OVER clause

SELECT
   school, board, col3, col4, ...,
   cnt_whoPassedA, ...,
   SUM(cnt_whoPassedA) OVER (PARTITION BY board) AS cnt_whoPassedA_ByBoard,
   SUM(cnt_whoPassedA) OVER (PARTITION BY school) AS cnt_whoPassedA_BySchool,
   SUM(cnt_whoPassedA) OVER (PARTITION BY school, board) AS cnt_whoPassedA_BySchoolBoard,
   ...
FROM
(
select 
 school, 
 board, 
 col3, col4, ...
 cnt_whoPassedA = SUM (CASE WHEN A.exam_PartA_score &gt; 50 THEN 1 ELSE 0 END)
 cnt_whoPassedB = SUM (CASE WHEN A.exam_PartA_score &gt; 50 THEN 1 ELSE 0 END)
from MyBigTable as A
group by A.school, A.board, A.col3, A.col4...
) T


However, I would consider doing this in my report layer (say in SSRS): do you need all levels of grouping at the same time?