The arabic and hebrew is really very crazy ... they for sure also would like
this very much, but it is not only that the writing direction is from right
to left, but the usually numbers are written "inverse" (as western style
from left to right).
Numbers in Arabic, Urdu, Persian, Hebrew, Maldivian are written left-to-right (even if their native script is right-to-left) like in Latin/modern Greek/Cyrillic/Chinese/Japanese/Korean/ (most significant digits first to the left) they are written right-to-left (but least significant digit first to the right) only for very long numbers when it would be dififcult for handwriters to estimage the space needed to write it correctly without collision.
However formulas (operations) are written right to left so where in Latin we would use "x = 1/2", in Arabic we would see "1/2 = x" or "2\1 = x" with the counter-slash for a more natural RTL reading order without changes of directions. And when spelled of course the numbers are written entirely right to left, with most significant number words first to the right. But Arabic culture has a long tradition of calligraphy including for numbers and appreciate cute presentation of math formulas and lot of tabular data for accounting purpose (with numbers naturally right aligned to the leastr significant figures, which is in fact more natural for them than for us).
We use the Arabic system for numbers since the end of Middle Age and the numerous contacts of European ships with the Arabic merchants in the Mediterranean Sea: the Semitic people were controling the fastest maritime route to Asia from India up to China, when the continental routes through central Asia were not only mluch longer, but in fact much more dangerous. We were very slow to almost abandon the old Roman and Greek numeral systems which proved to be impractical not just for science, but more importantly for commerce and the collection of taxes and control of the money by nobility and clergy. Arabic disseminated the introduction of zero and the positional system in all cultures of the then known world (except Americas, but the Arabic system reached South East Asia and even native tribes of Northern Australia and later remote islands of the Pacific starting from Taiwan then Java, the rest of Indonesia, New Guinea. Mainland China, Japan, Korea got the Arabic system very late even if there were limited contact with India, but more contacts with Turco-Mongols that invaded them from the North and East but with very little commerce: the decimal system started with the creation of Silk roads in Central Asia when Mongols were finally isolated from Turks, by the growth of the
Russian and Persian Empires (the later's islamisation started much later than Semitic regions still controled by Turks, but the influence of the Arabic fleets was decisive to spread rapidly the system all around the Indian Ocean, even in non-islamic cultures against which they were constantly in war, before the western colonisations).
Si you still think that Arabic and Hebrew are "crazy" ? What was crazy was the Roman system, derived from the Greek system, itself derived from Egyptians, and Pheonician Cuneiform (rod counting before they tought about assigning magic to the new base letters and use them for lunar calendars and later for commercial purpose with the introduction of currencies, instead of inconsistant weights or volumes of non reliable food and materials)... Well historicallky Hebrew has kept some magic for old texts refering to "divine" meaning of Hebrew letters and their association to celestial objects.
Arabs however did not invent the concept of digits (distinct from letters and detached from esoteric meaning), they borrowed it from India via the Persian empire, and then added the zero. They invented the decimal positional system using only 10 digits instead of many more digits that were still not enough for the commerce made by large fleets and with their neighbor kingdoms with which they signed some treaties after deadly wars, notably for ransoms and slavery of people in conquested areas.
The decisive entry of the Arabic numeral system in the "western world" was made under influence of the Venezian and Genoves merchants that found pacts with Arabs to commerce their spices, colors, perfumes, gems, gold, silk, coton, perls, fishery product, food, arms, jewelry and many artistic products (art was much more active in the Arab, Persian, and Asia in general than they were in Europe in the Middle Age after the collapse of the Roman Empire: culture regressed a lot when church capitalized it on a dying language that people no logner understood, allowing kingdoms to develop as deadly dictatures...).
The next decisive step for the universalisation of the Arabic system was the Reconquista in Spain: Europe was how much the Arabic cultures were developed and had progressed in all sciences to their economic advantage.
