Id     Grade 1    Grade 2    Grade 3
  1       1           1         1
  2       5           0         0
  3       3           1         5

Id     Grade 1    Grade 2    Grade 3      Total
  1       1           1         1            3
  2       5           0         0            8
  3       3           1         5            17

select
t.*,
@rolling_sum := @rolling_sum + `Grade 1` + `Grade 2` + `Grade 3` AS Total
from
Table1 t
, (select @rolling_sum := 0) var_init
order by id

select t.*,
(select sum([Grade 1] + [Grade 2] + [Grade 3]) from Table1 sub_t where sub_t.id <= t.id)
from Table1 t
order by id

SELECT A.*, (@runtot := @runtot + `Grade 1` + `Grade 2` + `Grade 3`) AS Total
FROM Table1 A
,(SELECT @runtot:=0) c

;with cte as (
    select
        id,
        grade1,
        grade2,
        grade3,
        isnull(grade1,0) + isnull(grade2,0) + isnull(grade3,0) as linetotal
    from grade
)
select *, total = (select sum(ss.linetotal) from cte ss where ss.id <= cte.id)
from cte