Forma 2 textbox , 1 label, 2 buton ekliyoruz.Program Alt programlarla yapılmıştır Sub,Function

Private Sub btntopla_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btntopla.Click
topla()
End Sub
Sub topla()
If txtsayi1.Text = "" And txtsayi2.Text = "" Then
MsgBox("Deger Giriniz")
Else
lblgoster.Text = txtsayi1.Text + +txtsayi2.Text

End If
End Sub

Private Sub btncikar_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btncikar.Click
cikar()
End Sub
Sub cikar()
If txtsayi1.Text = "" And txtsayi2.Text = "" Then
MsgBox("Deger Giriniz")
Else
lblgoster.Text = txtsayi1.Text - txtsayi2.Text

End If
End Sub

Private Sub btncarp_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btncarp.Click
carp()
End Sub
Sub carp()
If txtsayi1.Text = "" And txtsayi2.Text = "" Then
MsgBox("Deger Giriniz")
Else
lblgoster.Text = txtsayi1.Text * txtsayi2.Text

End If
End Sub

Private Sub btnbol_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnbol.Click
bol()
End Sub
Sub bol()
If txtsayi1.Text = "" And txtsayi2.Text = "" Then
MsgBox("Deger Giriniz")
Else
lblgoster.Text = txtsayi1.Text / txtsayi2.Text

End If
End Sub