On Ancient Numerals

Am I the only one whose ever wondered why the Ancients have symbols for 8 and 9 if they were a base-8 culture?

I mean, as base-8 (octal) they should have symbols for 0-7, but after that things should start repeating - ie, "8" in base-8 should be a lot like "10" in a base-10 system, utilising some combination of the original 8 symbols to indicate they first full set - at least, if it's a positional system, which evidence would seem to suggest

So why? Why have symbols for 2 numbers which, theoretically, would not exist?

The best reason I can think of is that, at some point, the Ancients wilfully converted from a base-10 system to a base-8, quite possibly for computer-related reasons - ie, most computers run off binary (base-2) number systems; perhaps the Ancients' run off of base-8 and, when they became a largely computer-oriented, space-faring, etc society, they no longer saw the point in using base-10 when their primary usage had become base-8.

Maybe. Possibly. But that's all I got. I'll work on it.
Hadn't even thought about this until now :D Reading that wiki article was interesting too. Do you think it might be possible that the Ancients used several systems in the past, like we on Earth have? I mean, maybe theirs didn't develop simultaneously everywhere either, and the 10-base numericals are sort of a leftover from that time. But I really don't have enough knowledge about all the details the show gave about the Ancients, so this is just me making a guess :)

Wonderful to see the alphabet too, is there any more info as to why certain letters are missing, and why f and u are the same?
true - we have Roman numerals but use Arabic numbers. But, still, those shared a similar base - and not a similar alphabet.

I've got nothing on "F" and "U" either, other than the creators were lazy and didn't notice they'd created duplicate symbols. but "fh" and "uuuu" kinda sound alike, so.... IDK?

No, wait, just checked wikipedia. the semetic letter "vav" - our F - was adopted into greek as "upsilion", a vowel that became our "Y", "U", "V" and "W". In Etruscan, "vav" became the "fh" sound, for which they used our letter "v", which is transliterated as a "u" in modern days, and the symbol for "f" came to mean just the "f" sound.

... I'll write that up all proper like when I figure out the number system.