ユーザーに 3 つの数値を 3 つのテキスト ボックスに入力して平均を求めさせようとしています。
Private Sub btnAverage_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAverage.Click
Dim a As Integer = CInt(txtone.Text)
Dim b As Integer = CInt(txtTwo.Text)
Dim c As Integer = CInt(txtThree.Text)
Dim average As Integer
average = (a + b + c) / 3
lstOutput.Text = average
End Sub