History of the Greek alphabet Plutarch criticizes Herodotus for prejudice and misrepresentation. Furthermore, he argues that "Gephyraei" were Euboeans or Eretrians and he doubts the reliability of Herodotus' sources. Plutarch and other ancient Greek writers credited the legendary Palamedes of Nauplion on Euboea with the invention of the supplementary letters not found in the original Phoenician alphabet. The distinction between "Eta" and "Epsilon" and between "Omega" and "Omicron", adopted in the Ionian standard, was traditionally attributed to Simonides of Ceos (556-469). Plutarch goes further back to describe an older Greek writing system, similar as he attested to the Egyptian writing. In his “Discourse Concerning Socrates’s
Greek alphabet letters were also used to write numbers. In the classical Ionian system, the first nine letters of the alphabet stood for the numbers from 1 to 9, the next nine letters stood for the multiples of 10, from 10 to 90, and the next nine letters stood for the multiples of 100, from 100 to 900. For this purpose, in addition to the 24 letters which by that time made up the standard alphabet, three otherwise obsolete letters were retained or revived: digamma for 6, koppa for 90, and a rare Ionian letter for [ss], today called sampi , for