How to end infinite “change” loop in VBA

Question

I have a problem with visual basic. I want to make a macro/function that will multiply a number I enter by 3 and give a result in the same cell. I tried something like this:

Answer 1

With error handling to ensure .EnableEvents goes back to True:

Sub Worksheet_Change(ByVal Target As Range)
    On Error GoTo CleanExit
    If Target.Address = "$Q$21" Then
        Application.EnableEvents = False
        Target.Value = Target.Value * 3
    End If
CleanExit:
    Application.EnableEvents = True
    On Error GoTo 0
End Sub