divide by zero while entering a numeric value that begins with 0

[nina_le_huynh]

basically I have a textbox

    Private Sub txt_NumberA_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txt_NumberA.TextChanged
        
        Try
            NumberA = Decimal.Parse(txt_NumberA.Text)
        Catch ex As Exception
            MsgBox("This program requires a numeric input.  Please try again. Enter .500 as 0.500.")
            Return
        End Try
        
        NumberB = 5.0
        
        NumberC = NumberB/NumberA

lbl_NumberC.Text = NumberC

    End Sub

I have no problem entering any number that does not start with a zero, however, if I want to enter 0.5 in, then as I type in '0', then I have division by zero and the program crashes.

Could you please help me to fix this? Many thanks,

Nina