(
	SELECT
		stuid as id,
		CAST(sum(case when `subject`='math' then score end) AS SIGNED) as math,
		CAST(sum(case when `subject`='english' then score end) AS SIGNED) as english,
		CAST((
			sum(case when `subject`='math' then score end)
			+
			sum(case when `subject`='english' then score end)
		) AS SIGNED) as 'sum'
	FROM
		score
	GROUP BY
	stuid
) 
UNION
(
	SELECT
		'avg' as id,
		CAST(avg(case when `subject`='math' then score end) AS SIGNED) as math,
		CAST(avg(case when `subject`='english' then score end) AS SIGNED) as english,
		CAST((
			avg(case when `subject`='math' then score end)
			+
			avg(case when `subject`='english' then score end)
		) AS SIGNED) as 'sum'
	FROM
		score
)