look a lot more like western arabic numbers; at least 1 2 3 and 7. I've been
to very old cathedrals in Germany, some of the uses of 4 was more like the
arab counterparts that is half of an 8. The 9s obviously looks similar. I
presume that 5 was changed due to similarities to the round zero.
In reality the arabic numbers should be called Indian numbers, since
the system was devised on the Indian subcontinent, it migrated to the west
through the Arab world. The principle innovation is the use of zero as a
place holder, zero as a concept was a novel and revolutionary idea (you'll
notice there isn't a zero in the roman number system) also significant is the
use of ascending powers of 10 in the arabic number system. (other cultures
used diffent bases to their number system, the roman system is arbitrary, but
Babylonians used base 60 and the ancient Maya used base 20).
In short while the western adaptation to arabic numbers may not look
identical they evolved from and are used exactly in the same way as arab
numbers.
