------considering execution for many rows-----------------

DECLARE @ExprCollection Table(expr VARCHAR(100) )

INSERT INTO @ExprCollection(expr)

SELECT '2+1'

UNION ALL

SELECT '5*2'

UNION ALL

SELECT '6/3'

DECLARE @genSql AS VARCHAR(MAX)

CREATE TABLE #ExpValueTable ([value] INT,[Id_Exp] [VARCHAR](100) PRIMARY KEY)

SELECT @genSql = CASE WHEN @genSql Is Null

THEN ' INSERT INTO #ExpValueTable ([value],[Id_Exp]) ' + ' SELECT ' + expr + ' AS ExpValue,''' + expr +''' As Exp'

ELSE @genSql + ' UNION SELECT ' + expr + ' AS ExpValue,''' + expr +''' As Exp' END

FROM @ExprCollection

GROUP BY expr

EXEC(@genSql)

SELECT *

FROM #ExpValueTable

--- OR JOIN YOUR TABLE TO THE TEMPORARY TABLE... AND BETTER USING THE TABLE PRIMARY KEY

DROP TABLE #ExpValueTable