Convert from twip to span

Unit Definition (twip)
A twip (which stands for Twentieth of a Point) is a typographical measurement. It is also used as the default measurement in Visual Basic. A twip is 1/1440 of an inch when derived from the PostScript point at 72 to the inch, as opposed to the printer's point at 72.27 to the inch.

Unit Definition (span)
Span is the width of a human hand, from the tip of the thumb to the tip of the pinky finger.