I already gave you a template. I will give you a template with more details. You will have to adapt it to your needs.

Class2:
Code:
Public Class Class2

    Private x As Int16 '32767

    Public Property Number() As Int16
        Get
            Return x
        End Get
        Set(ByVal value As Int16)
            x = value
        End Set
    End Property

End Class
Class3:
Code:
Public Class Class2

    Private x As Int16 '32767

    Public Property Number() As Int16
        Get
            Return x
        End Get
        Set(ByVal value As Int16)
            x = value
        End Set
    End Property

End Class
Class1 has customized CType functions to convert from Class1 and Class2. These functions are not perfect and can cause exceptions. They are merely for demonstration:
Code:
Public Class Class1

    Private x As Int32 '2147483647 

    Public Property Number() As Int32
        Get
            Return x
        End Get
        Set(ByVal value As Int32)
            x = value
        End Set
    End Property

    Public Shared Widening Operator CType(ByVal intNumber As Class2) As Class1
        Dim sngNumber As New Class1
        sngNumber.Number = Convert.ToInt32(intNumber.Number)
        Return sngNumber
    End Operator

    Public Shared Narrowing Operator CType(ByVal dblNumber As Class3) As Class1
        Dim sngNumber As New Class1
        If dblNumber.Number <= 2147483647 And dblNumber.Number >= -2147483648 Then
            sngNumber.Number = Convert.ToInt32(dblNumber.Number)
        End If
        Return sngNumber
    End Operator

End Class
If you wish to text it out then create a form with 3 textboxes and two buttons. You don't have to, but it may help to add 3 labels to the textboxes. Textbox1 is the results of the conversion, the contents of class1. Textbox2 will set the contents of Class2. Ditto with 3. Button1 converts Class2 to Class1. Button2 converts Class3 to Class1.
Form code:
Code:
Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim C1 As Class1
        Dim C2 As New Class2

        C2.Number = Int16.Parse(TextBox2.Text)
        C1 = CType(C2, Class1)

        TextBox1.Text = C1.Number.ToString

    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        Dim C1 As Class1
        Dim C3 As New Class3

        C3.Number = Int64.Parse(TextBox3.Text)
        C1 = CType(C3, Class1)

        TextBox1.Text = C1.Number.ToString

    End Sub
End Class