Probleme sur calculatrice vba

Bonjour,


je sais que c'est un sujet que vous avez du voir et revoir mais meme en cherchant partout je ne vois pas ce qui fait que dans mon programme le resultat est toujours de 0
si vous pouviez m'aider....
voila mon code


Private Sub numero0_Click()
TextBox_Operations.Text = TextBox_Operations.Text & "0"
End Sub
Private Sub numero1_Click()
TextBox_Operations.Text = TextBox_Operations.Text & "1"
End Sub
Private Sub numero2_Click()
TextBox_Operations.Text = TextBox_Operations.Text & "2"
End Sub
Private Sub numero3_Click()
TextBox_Operations.Text = TextBox_Operations.Text & "3"
End Sub
Private Sub numero4_Click()
TextBox_Operations.Text = TextBox_Operations.Text & "4"
End Sub
Private Sub numero5_Click()
TextBox_Operations.Text = TextBox_Operations.Text & "5"
End Sub
Private Sub numero6_Click()
TextBox_Operations.Text = TextBox_Operations.Text & "6"
End Sub
Private Sub numero7_Click()
TextBox_Operations.Text = TextBox_Operations.Text & "7"
End Sub
Private Sub numero8_Click()
TextBox_Operations.Text = TextBox_Operations.Text & "8"
End Sub
Private Sub numero9_Click()
TextBox_Operations.Text = TextBox_Operations.Text & "9"
End Sub

Private Sub addition_Click()
Dim nombre1 As Single
Dim nombre2 As Single
Dim resultat As Single
Dim operation As String
nombre1 = Val(TextBox_Operations.Text)
TextBox_Operations.Text = ""
operation = "+"
End Sub


Private Sub soustraction_Click()
Dim nombre1 As Single
Dim nombre2 As Single
Dim resultat As Single
Dim operation As String
nombre1 = Val(TextBox_Operations.Text)
TextBox_Operations.Text = ""
operation = "-"
End Sub

Private Sub multiplication_Click()
Dim nombre1 As Single
Dim nombre2 As Single
Dim resultat As Single
Dim operation As String
nombre1 = Val(TextBox_Operations.Text)
TextBox_Operations.Text = ""
operation = "*"
End Sub
Private Sub division_Click()
Dim nombre1 As Single
Dim nombre2 As Single
Dim resultat As Single
Dim operation As String
nombre1 = Val(TextBox_Operations.Text)
TextBox_Operations.Text = ""
operation = "/"
End Sub


Private Sub point_Click()
TextBox_Operations.Text = TextBox_Operations.Text & "."
End Sub

Private Sub reinitialiser_Click()
TextBox_Operations.Text = ""
End Sub

Private Sub resultat_Click()
Dim nombre1 As Single
Dim nombre2 As Single
Dim resultat As Single
Dim operation As String
nombre2 = Val(TextBox_Operations.Text)
If operation = "+" Then
resultat = nombre1 + nombre2
End If
If operation = "-" Then
resultat = nombre1 - nombre2
End If
If operation = "*" Then
resultat = nombre1 * nombre2
End If
If operation = "/" Then
resultat = nombre1 / nombre2
End If
TextBox_Operations.Text = resultat
End Sub