Do not count page number for hidden slides in PPT

power_point_hidden_slide_number.vba

' Open VBA Editor with Alt + F11
' Insert > Module
' Pase code underneath and press F5 to run
' Source: https://stackoverflow.com/a/26469723
Sub Number_NonHidden()
    'For v.2007 onwards only
    Dim osld As Slide
    Dim objSN As Shape
    Dim lngNum As Long
    'check all slides
    lngNum = -2
    For Each osld In ActivePresentation.Slides
        'Is it hidden
        If osld.SlideShowTransition.Hidden Then
            osld.HeadersFooters.SlideNumber.Visible = False
        Else
            osld.HeadersFooters.SlideNumber.Visible = True
            Set objSN = getNumber(osld)
            lngNum = lngNum + 1
            If Not objSN Is Nothing Then ' there is a number placeholder
                objSN.TextFrame.TextRange = CStr(lngNum + 1)
            End If
        End If
    Next osld
End Sub

Function getNumber(thisSlide As Slide) As Shape
    For Each getNumber In thisSlide.Shapes
        If getNumber.Type = msoPlaceholder Then
            If getNumber.PlaceholderFormat.Type = ppPlaceholderSlideNumber Then
                'it's the slide number
                Exit Function
            End If
        End If
    Next getNumber
End Function