Codigo en visual basic 2008 para calculadora sencilla

Option Explicit On
Public Class Calculadora
Dim primernumero As Single
Dim segundonumero As Single
Dim resultadocalculo As Single
Dim calculo As String
Private Subcdm1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cdm1.Click
txtDisplay.Text = txtDisplay.Text & "1"
End Sub
Private Sub cdm2_Click(ByVal sender AsSystem.Object, ByVal e As System.EventArgs) Handles cdm2.Click
txtDisplay.Text = txtDisplay.Text & "2"
End Sub
Private Sub cdm3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)Handles cdm3.Click
txtDisplay.Text = txtDisplay.Text & "3"
End Sub
Private Sub cdm4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cdm4.ClicktxtDisplay.Text = txtDisplay.Text & "4"
End Sub
Private Sub cdm5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cdm5.Click
txtDisplay.Text = txtDisplay.Text& "5"
End Sub
Private Sub cdm6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cdm6.Click
txtDisplay.Text = txtDisplay.Text & "6"
End Sub
PrivateSub cdm7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cdm7.Click
txtDisplay.Text = txtDisplay.Text & "7"
End Sub
Private Sub cdm8_Click(ByVal sender AsSystem.Object, ByVal e As System.EventArgs) Handles cdm8.Click
txtDisplay.Text = txtDisplay.Text & "8"
End Sub
Private Sub cdm9_Click(ByVal sender As System.Object, ByVal e AsSystem.EventArgs) Handles cdm9.Click
txtDisplay.Text = txtDisplay.Text & "9"
End Sub
Private Sub cdm0_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handlescdm0.Click
txtDisplay.Text = txtDisplay.Text & "0"
End Sub
Private Sub cdm10_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cdm10.Click
txtDisplay.Text...