Is there a reasoning behind the depiction of the numbers as they are $\{1$, $2$, $3$, $4$, $5$, $6$, $7$, $8$, $9\}$?

Question

Is there a reasoning behind the depiction of the numbers as they are: $$\{1,2,3,4,5,6,7,8,9\}$$

Is there any other form of depiction for $6$ and $9$ other than $VI$ and $IX$?

Answer 1

The image below depicts numbers in Japanese.

Answer 2

The first few are derived from ways to make $n$ marks.

http://en.wikipedia.org/wiki/Arabic_numerals#Origins

Answer 3

At this link you’ll find links to descriptions of almost three dozen numeral systems. Some of them share a common origin with our familiar numerals $0,1,\dots,9$, and some are completely different in origin. The Brahmi numerals are the direct graphic ancestors of our numerals; as you can see from the picture there, the first three were basically just tally marks, but the rest have no obvious pictorial significance.