Numeral
Digamma/wau remained in use in the system of Greek numerals attributed to Miletus, where it stood for the number 6, reflecting its original place in the sequence of the alphabet. It was one of three letters that were kept in this way in addition to the 24 letters of the classical alphabet, the other two being koppa (ϙ) for 90, and sampi (ϡ) for 900. During their history in handwriting in late antiquity and the Byzantine era, all three of these symbols underwent several changes in shape, with digamma ultimately taking the form of "ϛ". It has remained in use as a numeral in Greek to the present day, in contexts such as enumerating chapters in a book or other items in a set.
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