Here is a new website dedicated to Greek and Roman numbers. Read what its creator’s description:
“Welcome to the Ancient Numbers Page. It is a work in progress, and many features will be added in the coming weeks and months.
“Aim: To help my students and the general public better understand ancient Greek and Roman numbers, and how they were represented. Different subpages will provide explanations, calculators, and graded quizzes. Some in each category are already done, and can be reached through the links in the User Menu on the left.”
Explore this website at http://www.nvmeri.org