Why is it that this works with the numerical value of the variable BMI (without the ToString), as well as BMI.ToString ? See below near bottom for lblBMI.Text.

Partial Class BMICalculator
    Inherits System.Web.UI.Page

    Protected Sub CalculateBMI_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles CalculateBMI.Click
        ' Find out the person's height and weight
        Dim UsersHeight As Integer = txtHeight.Text
        Dim UsersWeight As Integer = txtWeight.Text

        ' Calculate the person's BMI.
        Dim BMI As Decimal
        BMI = (UsersWeight / (UsersHeight * UsersHeight)) * 703

        ' Output the BMI value.
        lblBMI.Text = "Your BMI is " & BMI.ToString
    End Sub
End Class