تفضل أخي الحبيب إبراهيم أبو ليلة 
Private Sub Worksheet_Change(ByVal Target As Range)
    On Error Resume Next
    If Target.Address = [F6].Address Then
        If IsEmpty(Range("F6")) Then
            Cells(8, 4).Value = ""
            Cells(9, 4).Value = ""
            Cells(10, 4).Value = ""
        Else
            Cells(8, 4) = 1
            Cells(9, 4) = 2
            Cells(10, 4) = 3
        End If
    End If
End Sub