select dbo.fx_getrandomnumber(500, 300, rand())
FROM dbo.Tally
WHERE N <= 10

select dbo.fx_getrandomnumber(500, 300, rand(CHECKSUM(NEWID())))
FROM dbo.Tally
WHERE N <= 10

 SELECT ABS(CHECKSUM(NEWID()))%(500-300+1)+300
   FROM dbo.Tally
  WHERE N <= 10

SELECT Number, COUNT(*) 
FROM (SELECT ABS(CHECKSUM(NEWID()))%(500-300+1)+300 AS Number
	FROM dbo.Numbers
	WHERE number <= 200
) d 
GROUP BY Number 
ORDER BY Number

SELECT Number, COUNT(*) as NumberCount
FROM (SELECT ABS(CHECKSUM(NEWID()))%(500-300+1)+300 AS Number
	FROM dbo.Numbers
	WHERE number <= 200
) d 
GROUP BY Number 
ORDER BY Number

Number      NumberCount 
----------- ----------- 
300         1
303         1
303         1
305         2
307         3
307         3
307         1
309         2

SELECT Number, SUM(NumberCount), count(*)
FROM (SELECT Number, COUNT(*) as NumberCount
	FROM (SELECT ABS(CHECKSUM(NEWID()))%(500-300+1)+300 AS Number
		FROM dbo.Numbers
		WHERE number <= 200
	) d 
	GROUP BY Number 
) d2
GROUP BY Number
ORDER BY Number

Number                              
----------- ----------- ----------- 
301         4           3
304         1           1
307         2           2
308         1           1
309         1           1