In message , at
15:20:49 on Mon, 27 Dec 2004, Martin Underwood
remarked:
I tend to break numbers into triplets, but if I knew the number before BT
added extra digits I break it at that point without even thinking about it:
my parents' number used to be 3698 and then was lengthened to 613698:
subconsciously I break this into 61 and 3698 rather than 613 698 ;-)

The breakpoint can affect the memorability very significantly. I have a
number that ends either 604 080, or 60 40 80, depending on where you
break it!
--
Roland Perry