How do I convert a indefinite decimal (i.e. .333333333...) to a string fraction representation (i.e. "1/3"). I am using VBA and the following is the code I used (i get an overflow error at the line "b = a Mod b":

Function GetFraction(ByVal Num As Double) As String

    If Num = 0# Then
        GetFraction = "None"
    Else
        Dim WholeNumber As Integer
        Dim DecimalNumber As Double
        Dim Numerator As Double
        Dim Denomenator As Double
        Dim a, b, t As Double

        WholeNumber = Fix(Num)
        DecimalNumber = Num - Fix(Num)
        Numerator = DecimalNumber * 10 ^ (Len(CStr(DecimalNumber)) - 2)
        Denomenator = 10 ^ (Len(CStr(DecimalNumber)) - 2)
        If Numerator = 0 Then
            GetFraction = WholeNumber
        Else
            a = Numerator
            b = Denomenator
            t = 0

            While b <> 0
                t = b
                b = a Mod b
                a = t
            Wend
            If WholeNumber = 0 Then
                GetFraction = CStr(Numerator / a) & "/" & CStr(Denomenator / a)
            Else
                GetFraction = CStr(WholeNumber) & " " & CStr(Numerator / a) & "/" & CStr(Denomenator / a)
            End If
        End If
    End If
End Function