problème de format fraction sous vba

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Count > 1 Then Exit Sub
If Not IsNumeric(CStr(Target)) Then Exit Sub
If Int(Target) = Target Then Exit Sub
Dim i As Byte
For i = 1 To 20
  Target.NumberFormat = String(i, "?") & "/" & String(i, "?")
  If Target = Evaluate(Target.Text) Then Exit For
Next
End Sub

Sub Essai()
MsgBox FChaineFraction(1.5)
End Sub

Public Function FChaineFraction(V!) As String
Dim I1%, I2%, V1%, V2!
V1 = Int(V!): V2 = V! - V1: FChaineFraction = Trim(V!) 'si pas de fraction retour val
For I1 = 1 To 99: For I2 = 1 To 99
 If I1 / I2 = V2 Then FChaineFraction = V1 & " " & I1 & "/" & I2: Exit Function
Next: Next
End Function

Function Fraction$(x)
If Not IsNumeric(x) Then Fraction = x: Exit Function
If Int(x) = x Then Fraction = x: Exit Function
Dim e, d, i&, j&
e = Int(x)
d = x - Int(x)
For i = 1 To 9998
  For j = 2 To 9999
   If Round(i / j - d, 8) = 0 Then Fraction = e * j + i & "/" & j: Exit Function
  Next j
Next i
Fraction = x
End Function

Sub Essai()
V! = 1.6 '< valeur

T! = Timer: Z$ = FChaineFraction(V!)
MsgBox Timer - T! & vbLf & Z$ '< j'obtient "1 3/4" ce dont je recherche

T! = Timer: Z$ = Fraction(V!)
MsgBox Timer - T! & vbLf & Z$ '< j'obtient rien !?

End Sub


Public Function FChaineFraction$(V!)
Dim I1%, I2%, V1%, V2!
V1 = Int(V!): V2 = V! - V1: FChaineFraction = Trim(V!) 'si pas de fraction retour val
For I1 = 1 To 9998: For I2 = 2 To 9999
 If I1 / I2 = V2 Then FChaineFraction = V1 & " " & I1 & "/" & I2: Exit Function
Next: Next
End Function

Function Fraction$(X)
If Not IsNumeric(X) Then Fraction = X: Exit Function
If Int(X) = X Then Fraction = X: Exit Function
Dim E, D, I&, J&
E = Int(X)
D = X - Int(X)
For I = 1 To 9998
  For J = 2 To 9999
   If Round(I / J - D, 8) = 0 Then Fraction = E * J + I & "/" & J: Exit Function
  Next J
Next I
Fraction = X
End Function

Z = Application.Text(V, "# ??/??")

Function FractionDec$(x)
If Not IsNumeric(x) Then FractionDec = x: Exit Function
If Int(x) = x Then FractionDec = x: Exit Function
Dim e, d, denum, num
e = Int(CDec(x))
d = CDec(x - e)
denum = CDec(10 ^ (Len(d) - 2))
num = CDec(d * denum)
While Right(num, 1) Mod 2 + Right(denum, 1) Mod 2 = 0
  num = num / 2: denum = denum / 2
Wend
While Right(num, 1) Mod 5 + Right(denum, 1) Mod 5 = 0
  num = num / 5: denum = denum / 5
Wend
FractionDec = IIf(e, e & " ", "") & num & "/" & denum
End Function

Function Fraction$(X)
If Not IsNumeric(X) Then Fraction = X: Exit Function
If Int(X) = X Then Fraction = X: Exit Function
Dim E, D, I&, J&
E = Int(X)
D = CDec(X - Int(X))
For I = 1 To 9998
  For J = 2 To 9999
   If Round(I / J - D, 8) = 0 Then Fraction = E * J + I & "/" & J: Exit Function
  Next J
Next I
Fraction = X
End Function

Function fr$(x, Optional p% = 2) '
'Renvoie, si possible, la meilleure approximation rationnelle
'de x dont le dénominateur possède au plus 'p' chiffres.
Dim a, b#, c#, d#, i%, f, g00, g01, g10, g11
  fr = x
  If IsNumeric(x) Then
    c = Abs(x)
    If c > 0 And c <> Int(c) Then
      d = 10 ^ p
      b = c: a = Int(c)
      g00 = 1: g10 = 0
      g01 = a: g11 = 1
      Do While Round(a - b, 12) <> 0 And i < 39 And g11 < d
        i = i + 1
        b = 1 / (b - a): a = Int(b)
        f = a * g01 + g00: g00 = g01: g01 = f
        f = a * g11 + g10: g10 = g11: g11 = f
      Loop
      If g11 < d Then g00 = g01: g10 = g11
      a = Int(g00 / g10): b = g00 - a * g10
      fr = IIf(x < 0, "-", "") & IIf(a > 0, a & " ", "") & IIf(g10 > 1, b & "/" & g10, "")
    End If
  End If
End Function