1234 became today's 1234 bit by bit through hieroglyphics. Check Liu Hui's book Nine Chapters Arithmetic in the Late Three Kingdoms. In ancient times, the counting method according to your meaning was Chinese characters. For example, "Cao Jun gathers 800,000 people" or "Jingzhou 600,000 defenders" is an abacus! ! That's all, there are not so many reasons! If you write 1000, it is the Chinese character "one thousand" 10000 "ten thousand" (traditional), which has not been expressed as systematically as "Arabic numerals".