4° programa
"Promedio de Calificaciones"

Public Class Form1

"suma de las calificaciones y su division"

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

TextBox4.Text = (Val(TextBox1.Text) + Val(TextBox2.Text) + Val(TextBox3.Text) / 3)

End Sub

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

End

End Sub

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click

TextBox1.Text = ""

TextBox2.Text = ""

TextBox3.Text = ""

TextBox4.Text = ""

End Sub

End Class