Dim pi As Decimal = 1
    Dim x As Integer
    Dim runs As Integer = 1
 
    Private Sub tmrTimer_Tick(ByVal sender As Object, ByVal e As  _
      System.EventArgs) Handles tmrTimer.Tick
        x = runs
        While x > 0
            pi = x * 2 - 1 + CType(x ^ 2, Decimal) / pi
            x = x - 1
        End While
        lblOut.Text = 4 / pi
        runs = runs + 1
    End Sub