Greek Numerals - Description

Description

Each unit (1, 2, …, 9) was assigned a separate letter, each tens (10, 20, …, 90) a separate letter, and each hundreds (100, 200, …, 900) a separate letter. This requires 27 letters, so the 24-letter Greek alphabet was extended by using three obsolete letters: digamma ϝ for 6, qoppa ϟ for 90, and sampi ϡ for 900. Digamma is today most often written in its modern form ϛ, which is also called stigma; in Greece it is often replaced by the letter combination στ/ΣΤ. To distinguish numerals from letters they are followed in modern print by the keraia (Greek κεραία, "hornlike projection"), a symbol ( ʹ ) similar to an acute sign ( ´ ) but with its own Unicode character (U+0374). In ancient and medieval manuscripts, number signs were written with a horizontal line above.

This alphabetic system operates on the additive principle in which the numeric values of the letters are added together to form the total. For example, 241 is represented as σμαʹ (200 + 40 + 1). A famous example is 666 (the number of the Beast), which is represented as χξϛʹ (600 + 60 + 6) in medieval manuscripts of the Book of Revelation.

To represent numbers from 1,000 to 999,999 the same letters are reused to serve as thousands, tens of thousands, and hundreds of thousands. A "left keraia" (Unicode U+0375, ‘Greek Lower Numeral Sign’) is put in front of thousands to distinguish them from the standard use. For example, 2011 is represented as ͵βιαʹ (2000 + 10 + 1).

In modern Greek, uppercase letters are preferred, as in Φίλιππος Βʹ = Philip II.