How Count Row Value in SQL Server database?
One way

SELECT 
      *,
      CASE WHEN [1] = 'A' THEN 1 ELSE 0 END + 
      CASE WHEN [2] = 'A' THEN 1 ELSE 0 END + 
      CASE WHEN [3] = 'A' THEN 1 ELSE 0 END + 
      CASE WHEN [4] = 'A' THEN 1 ELSE 0 END AS TotalA
FROM TimeSheet


or

SELECT *,
       (SELECT count(*)
        FROM   (VALUES([1]),
                      ([2]),
                      ([3]),
                      ([4])) V(c)
        WHERE  c = 'A') AS TotalA
FROM   TimeSheet