Cant get this user input value to reference

Module Module1

    Sub Main()

        Dim CalcAgain As String = "y"

        While CalcAgain = "Y" Or CalcAgain = "y"
            Dim score As Integer
            Dim Counter As Integer = 5
            Dim Average As Integer
            Dim Count As Integer = 5
            Dim LetterGrade = ""
            Dim Accumulator As Decimal = 0

            Chart()
            LetterGrade = DetermineGrade(Average, score, LetterGrade)
            Average = CalcAverage(Counter, Accumulator)
            Accumulator = Accumulator + score

            For Counter = 1 To Count
                Console.Write("Please enter a test score: ")
                score = Console.ReadLine()
                Console.WriteLine("Letter: " & LetterGrade)
                While score > 100 Or score < 1
                    Count = Count + 1
                    Console.WriteLine("Invalid entry Pease enter a Numeric test score")
                    Console.WriteLine("between 0 and 100. Please re-enter your score:")
                    score = Console.ReadLine()
                End While
            Next


            DisplyResults(CalcAgain, score, Average, LetterGrade)

            Console.WriteLine("Would you like to calculate again? (y/n)")
            CalcAgain = Console.ReadLine()
        End While
    End Sub


End Module
Module GradeChart
    Sub Chart()
        Console.WriteLine("Grading Chart")
        Console.Write("Score")
        Console.Write(vbTab & vbTab & "Grade")
        Console.Write(vbCrLf & "90 - 100")
        Console.Write(vbTab & "A")
        Console.Write(vbCrLf & "80 - 89" & vbTab)
        Console.Write(vbTab & "B")
        Console.Write(vbCrLf & "70 - 79" & vbTab)
        Console.Write(vbTab & "C")
        Console.Write(vbCrLf & "60 - 69" & vbTab)
        Console.Write(vbTab & "D")
        Console.Write(vbCrLf & "Below 60")
        Console.Write(vbTab & "F")
        Console.WriteLine("")
        Console.WriteLine("Press any Key to Begin...")
        Console.ReadKey()
    End Sub
End Module
Module getAverage
    Function CalcAverage(ByRef Counter As Integer, ByRef Accumulator As Decimal) As Integer
        Dim Average As Integer
        Average = Accumulator / Counter
        Return Average
    End Function
End Module
Module GradeConversion
    Function DetermineGrade(ByRef Average As Integer, ByRef Score As Integer, ByRef LetterGrade As String) As String
        If (Score <= 100) And (Score >= 90) Then
            LetterGrade = "A"
        ElseIf (Score <= 89) And (Score >= 80) Then
            LetterGrade = "B"
        ElseIf (Score <= 79) And (Score >= 70) Then
            LetterGrade = "C"
        ElseIf (Score <= 69) And (Score >= 60) Then
            LetterGrade = "D"
        ElseIf Score < 60 Then
            LetterGrade = "F"
        End If
        Return LetterGrade
    End Function
End Module
Module Results
    Sub DisplyResults(ByRef CalcAgain As String, ByVal Score As Integer, ByRef Average As Integer, ByRef LetterGrade As String)
        Score = Average
        Console.WriteLine("Your average is: ")
        Console.WriteLine()
        Console.Write("Score")
        Console.Write(vbTab & "Letter")
        Console.Write(vbCrLf & Average)
        Console.Write(vbTab & LetterGrade)
    End Sub
End Module