Module Code:

'Output is string
'String output = "WholeNumber Numerator/Denominator"
Function SimFraction (WholeNumber As Integer, Numerator As Integer, Denominator As Integer) as string
    
    Dim Num As Double
    Dim Den As Double
    Dim Whole As Double
    
    Num = Numerator
    Den = Denominator
    Whole = WholeNumber
    
    ReDim NumRng(1 To (Num + Den))
    ReDim DenRng(1 To (Num + Den))
    
    For I = 1 To Num
        Q = Num / I
        IQ = Int(Q)
        If Q = IQ Then NumRng(I) = True
    Next
    
    For I = 1 To Den
        Q = Den / I
        IQ = Int(Q)
        If Q = IQ Then DenRng(I) = True
    Next
    
    For I = 1 To Den
        If NumRng(I) = True Then
            If NumRng(I) = DenRng(I) Then
                If I > A Then
                    A = I
                End If
            End If
        End If
    Next
    
    NumAns = Num / A
    DenAns = Den / A
    
    If NumAns > DenAns Then
        W = NumAns / DenAns
        IW = Int(W)
        If IW > W Then IW = IW - 1
        Frt = NumAns - (IW * DenAns)
        If Frt <> 0 Then
            simFraction = (IW + Whole) & " " & Frt & "/" & DenAns
        ElseIf Frt = 0 Then
            simFraction = IW + Whole
        End If
    Else
        If NumAns = DenAns Then
            Solution = NumAns + Whole
        Else
            If Whole = 0 Then
                SimFraction = NumAns & "/" & DenAns
            Else
                simFraction = Whole & " " & NumAns & "/" & DenAns
            End If
        End If
    End If
End Function