Numbers and Punctuation
By the middle of the 2nd millennium BC, the Babylonian mathematics had a sophisticated sexagesimal positional numeral system. The lack of a positional value (or zero) was indicated by a space between sexagesimal numerals. By 300 BC, a punctuation symbol (two slanted wedges) was co-opted as a placeholder in the same Babylonian system. In a tablet unearthed at Kish (dating from about 700 BC), the scribe Bêl-bân-aplu wrote his zeros with three hooks, rather than two slanted wedges.
The Babylonian placeholder was not a true zero because it was not used alone. Nor was it used at the end of a number. Thus numbers like 2 and 120 (2×60), 3 and 180 (3×60), 4 and 240 (4×60) looked the same because the larger numbers lacked a final sexagesimal placeholder. Only context could differentiate them.
The decimal Hindu-Arabic numeral system was invented in India around 500 CE. The system was revolutionary by including a zero and positional notation. It is considered an important milestone in the development of mathematics. One may distinguish between this positional system, which is identical throughout the family, and the precise glyphs used to write the numerals, which vary regionally. The glyphs most commonly used in conjunction with the Latin script since early modern times are 0 1 2 3 4 5 6 7 8 9. The first universally accepted inscription containing the use of the 0 glyph is first recorded in the 9th century, in an inscription at Gwalior in Central India dated to 870. By this time, the use of the glyph had already reached Persia, and was mentioned in Al-Khwarizmi’s descriptions of Indian numerals. Numerous Indian documents on copper plates exist, with the same symbol for zero in them, dated back as far as the 6th century CE.
Modern-day Arab telephone keypad with two forms of Arabic numerals: Western Arabic/European numerals on the left and Eastern Arabic numerals on the right
The numeral system came to be known to both the Persian mathematician Al-Khwarizmi, whose book On the Calculation with Hindu Numerals written about 825 in Arabic, and the Arab mathematician Al-Kindi, who wrote four volumes, “On the Use of the Indian Numerals” (Ketab fi Isti’mal al-‘Adad al-Hindi) about 830. Their work was principally responsible for the diffusion of the Indian system of numeration in the Middle East and the West. In the 10th century, Middle-Eastern mathematicians extended the decimal numeral system to include fractions, as recorded in a treatise by Syrian mathematician Abu’l-Hasan al-Uqlidisi in 952–953. The decimal point notation was introduced by Sind ibn Ali, he also wrote the earliest treatise on Arabic numerals.
A distinctive West Arabic variant of the symbols begins to emerge around the 10th century in the Maghreb and Al-Andalus, called ghubar (“sand-table” or “dust-table”) numerals, which are the direct ancestor of the modern Western Arabic numerals used throughout the world. Ghubar numerals themselves are probably of Roman origin.
The first writing systems were either logographic or syllabic—for example, Chinese and Maya script—which do not necessarily require punctuation, especially spacing. This is because the entire morpheme or word is typically clustered within a single glyph, so spacing does not help as much to distinguish where one word ends and the other starts. Disambiguation and emphasis can easily be communicated without punctuation by employing a separate written form distinct from the spoken form of the language that uses slightly different phraseology. Even today, formal written modern English differs subtly from spoken English because not all emphasis and disambiguation is possible to convey in print, even with punctuation.
Ancient Chinese classical texts were transmitted without punctuation. However, many Warring states era bamboo texts contain the symbols 「└」 and 「▄」 indicating the end of a chapter and full stop, respectively. By the Song dynasty, addition of punctuation to texts by scholars to aid comprehension became common.
The earliest alphabetic writing had no capitalization, no spaces, no vowels and few punctuation marks. This worked as long as the subject matter was restricted to a limited range of topics (e.g., writing used for recording business transactions). Punctuation is historically an aid to reading aloud: vis George Bernard Shaw.
The oldest known document using punctuation is the Mesha Stele (9th century BC). This employs points between the words and horizontal strokes between the sense section as punctuation.