t-sql 2008 r2 use results from a temp table

In 2008 t-sql  I have the sql listed below where I obtain results by calling a stored procedure  [test].[dbo].[sroom]. I am joining the results from calling a stored procedure with an existing table called Transactions. I am joining the 2 tables by the value by the SchoolNumber and the school.

The problem is that sometimes there is more than one row returned by the stored procedure by the studentNumber. The student number is not a unique key. The problem is that more than one studentNumber data row can be returned by the query below. My problem is that I only want 1 row for each studentnumber.

I have tried to select top 1 for the sql listed below with no success. Thus can you show me modifed sql listed below where only one row for each unique studentNumber in the temp table called #hResults is joined to the test.dbo.Transactions table? The user does not care what row is returned by  studentNumber they just want one row returned.

IF OBJECT_ID('tempdb..#hResults') IS NOT NULL
         DROP table studentNumber
 
CREATE TABLE #hResults(
                 personID INT,
                 studentNumber VARCHAR(15),   
   firstName VARCHAR(35),
   middleName VARCHAR(30),
                 lastName VARCHAR(40),
          suffix VARCHAR(50),
   fullName VARCHAR(108),
   enrollmentID INT,
   structureID INT,
   grade VARCHAR(4),               
   calendarID INT,
   calendarName  VARCHAR(30),
   endYear SMALLINT,
                 schoolNumber VARCHAR(7),
   schoolName VARCHAR(40),   
   courseID INT,
   courseNumber VARCHAR(13),
   courseName VARCHAR(30),               
   sectionID INT,
   sectionNumber SMALLINT,
   homeroomSection BIT,   
   teacherDisplay VARCHAR(30),
                 teacherPersonID INT)
 
     INSERT  #hResults
       EXEC [test].[dbo].[sroom] @endYear, @calendarID, N'C' 
 
   
SELECT s.SchoolNumber,
        s.SchoolName,
 homeroom.courseNumber , 
 homeroom.sectionNumber AS Section,  
 homeroom.teacherDisplay as Teacher,  
        f.StudentNumber,
       replace(StudentLastName,'"','') + ' ' + replace(StudentFirstName,'"','')
           as 'Student Name'
      ,TransactionAmount
      ,CONVERT(smalldatetime,substring(TransactionPaymentDate,5,4) + '-' +
substring      (TransactionPaymentDate,1,2)+ '-' +
substring(TransactionPaymentDate,3,2)) as        TransactionPaymentDate     
      from test.dbo.Transactions f
       INNER JOIN
    test.dbo.Schools s      
    on rtrim(ltrim(s.SchoolNumber)) =rtrim(ltrim( f.SchoolNumber))
    LEFT JOIN #hResults homeroom
    ON homeroom.studentNumber = f.StudentNumber 
      WHERE rtrim(ltrim(s.SchoolNumber)) = rtrim(ltrim(@SchoolNumber))            
      AND
      Cast(Right(TransactionPaymentDate,4)+Left(TransactionPaymentDate,4)  as
Date)
        >= @StartDate
     AND
   Cast(Right(TransactionPaymentDate,4)+Left(TransactionPaymentDate,4)  as Date)
<= @EndDate
   group by  s.SchoolNumber,
             s.SchoolName,
      homeroom.courseNumber,    
      homeroom.sectionNumber,
      homeroom.roomName, 
      homeroom.teacherDisplay, 
             f.StudentNumber,
             replace(StudentLastName,'"','') + ' ' +
replace(StudentFirstName,'"','')
             ,TransactionAmount
             ,TransactionPaymentDate
             ,TransactionPaymenttime
             ,PaymentType
             ,EventNumber            
             homeroom.courseNumber, 
      homeroom.sectionNumber,
      homeroom.roomName, 
      homeroom.teacherDisplay, 
             StudentNumber,
             TransactionPaymentDate
 
 IF OBJECT_ID('tempdb..#hResults') IS NOT NULL
    DROP table #hResults 
 
 Thus can you show me modifed sql listed above where only one row for each unique studentNumber in the temp table called #hResults is joined to the test.dbo.Transactions table?