DECLARE @t TABLE(value VARCHAR(10),xml_1 XML)
INSERT INTO @T(value,xml_1)
VALUES('1+2','<root><s>1</s><s>2</s></root>'),
      ('3+4','<root><s>3</s><s>4</s></root>')

SELECT value,x.r.value('.','INT') AS s
FROM @t
CROSS APPLY xml_1.nodes('/root/s') AS x(r)