Α - Β - Γ - Δ - Ε -ΣΤ etc - Greek numeric system (using greek alphabet characters)
I - II - III -IV - V etc -Roman (Latin numeric system)
1 - 2 - 3 - 4 - 5 etc - Arabic (current international numeric system)
am I won?
Yes. You won that game because you remembered to include the letter Stigma. (where digamma/F ended up later...)
Now add the Minoan numeric system, a permutation of Egypitian decimal, with 5 sets of characters depending on distance from the dot. Oh and the Egyptian decimal system goes out to at least 7, though not entirely logically.
Then for even brainier fun, look at the Basque Millers' Signs, a remnant of one of the systems from which Roman (I V X L C M etc) derived. The Millers' Signs are vigesimal (base 20), with distinct marks for 1, 5, 10, 20, 40, 60, 80. Mayan numerals are also vigesimal, though their repertoire seems to be 1, 5, 0.
Or for a deeper look at where our own letters came from, have a look at Ugarit ca. 1300 BCE, attested in two versions:
A B G X D E W Z H T' Y K S L M Dh N Z' S1 O P S' Q R Th Gh T I U Sh
E L H M Q W S R T S1 K N X B Sh F2 A O Z' G D Gh T' Z Dh Y Th S' Dh'
... and they used either set for numerals. Greek letters are a sloppy version of that first set, Arabic letters are a much less sloppy version of the second.
/totalTangent offered for your entertainment