Public Class Form1
    Dim Sep As Char
    Dim Número As Double

    Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        If Not (Char.IsNumber(e.KeyChar) Or e.KeyChar.Equals(Sep) Or Char.IsControl(e.KeyChar)) Then e.Handled = True
    End Sub

End Class

 Public Class Form1
    Dim r1, r2, r3, r4, r5, r6 As Integer

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        r1 = Val(TextBox1.Text)
        TextBox2.Text = r1 + 1
        TextBox3.Text = r1 + 2
        TextBox4.Text = r1 + 3

    End Sub

    Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged

    End Sub

    Private Sub TextBox5_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox5.TextChanged

    End Sub
End Class