and yet another way...

Code:
Private Sub CommandButton1_Click()
Dim dividend As String
Dim divisor As String
Dim info As String
Dim Split As Integer

' Start with this.
info = TextBox1.Text
' Find the Division.
Split = InStr(1, info, "/", vbTextCompare)

dividend = Left(info, Split - 1)

divisor = Right(info, Split + 1)
Label1.Caption = dividend / divisor

End Sub