A complete writing system in Chinese characters appeared 3200 years ago, making it perhaps the oldest surviving writing system. Various neolithic signs, which were found in what is today China, and which date back as early as the 7th millennium BC, may represent possible precursors of the Chinese script, although there has been no direct link established so far.
Four percent of Chinese characters are derived directly from individual pictograms , and in most of those cases the relationship is not necessarily clear to the modern reader. The other 96% are logical aggregates, which are characters combined from multiple parts indicative of meaning, and pictophonetics, characters containing two parts where one indicating a general category of meaning and the other the sound, though the sound is often only approximate to the modern pronunciation because of changes over time and differences between source languages. The number of Chinese characters contained in the Kangxi dictionary is approximately 47,035, although a large number of these are rarely-used variants accumulated throughout history. In China, literacy for the working citizen is defined as knowledge of 2,000 characters.
