I This letter is the most familiar and we use it unconsciously
to number our chapters in books. It represents a number one.
II If we add two 'I's together it represents the number
two.
III And three 'I''s represents the number three.
IIII Have you seen a number four represented in this
way? If you look closely at the old clocks that use Roman numerals,
this is exactly what you will see. It makes sense that if you
add four 'I''s you'll count till the number four. However
this can become cumbersome to represent the number two hundred
and one using just two hundred and one 'I''s. So the Romans started
using a newer letter for every fifth increment. This is
the familiar letter 'V'.
IV You may, however, be more familiar with the 'IV'
representation of the number four used in most chapter books. This
is a way of representing one less than five. Because
the lower value 'I' (one) is written before the higher
value 'V' (five), it means take one from five.