Definition:Greek Numerals
Definition
Attic System
The Greek numerals from the Attic period (c. 500 BCE to c. 300 BCE) are similar to the Roman system:
\(\displaystyle \textsf{I}:\) | \(\) | \(\displaystyle \)one\(\) | |||||||||||
\(\displaystyle \Pi:\) | \(\)penta\(:\) | \(\displaystyle \)five\(\) | |||||||||||
\(\displaystyle \Delta:\) | \(\)deka\(:\) | \(\displaystyle \)ten\(\) | |||||||||||
\(\displaystyle \Eta:\) | \(\)hekaton\(:\) | \(\displaystyle \)one hundred\(\) | |||||||||||
\(\displaystyle \Xi:\) | \(\)chilioi\(:\) | \(\displaystyle \)one thousand\(\) | |||||||||||
\(\displaystyle \Mu:\) | \(\)myriad\(:\) | \(\displaystyle \)ten thousand\(\) |
$\Pi$ was later written in a different form, with a shorter right leg, and from there it appears to have evolved into $\Gamma$.
Numbers were combined in a similar way to Roman numbers, but with additive forms only.
For example, $32718$ would have been written $\Mu \Mu \Mu \Xi \Xi \Eta \Eta \Eta \Eta \Eta \Eta \Eta \Delta \Pi \textsf {III}$.
Later evolutions introduced symbols for $50$, $500$ and $5000$, consisting of a tiny version of the appropriate power of $10$ nestled under the right hand (short) branch of the short-leg version of $\Pi$.
Such characters are difficult to render neatly, and as they are of limited importance, this has not been attempted on $\mathsf{Pr} \infty \mathsf{fWiki}$.
Classical Period
The Greek numerals from the Classical period (c. $600$ BCE to c. $300$ BCE) are as follows:
- $\begin{array}{ccccccccc} 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 \\ \alpha & \beta & \gamma & \delta & \epsilon & stigma & \zeta & \eta & \theta \\ \hline \\ 10 & 20 & 30 & 40 & 50 & 60 & 70 & 80 & 90 \\ \iota & \kappa & \lambda & \mu & \nu & \xi & \omicron & \pi & koppa \\ \hline \\ 100 & 200 & 300 & 400 & 500 & 600 & 700 & 800 & 900 \\ \rho & \sigma & \tau & \upsilon & \phi & \chi & \psi & \omega & sampi \\ \end{array}$
where $stigma$, $koppa$ and $sampi$ are characters that are not supported by MathJax.
These were the letters of the everyday Greek alphabet, with extra ones added from the Phoenician alphabet.
As it could be easy to confuse numbers with the letters of Greek words, a line was written over the numbers to distinguish them.
Numbers bigger than $999$ could be written by putting a stroke in front of the symbols.
Sources
- 2008: Ian Stewart: Taming the Infinite ... (previous) ... (next): Chapter $3$: Notations and Numbers