So, I'm in the middle of this biography of a medieval philosopher (yea, I know; laugh-a-minute) and found a good (more importantly concise!) explanation of how math and numbers worked before the Arabs gave us their numerals from India. It also contains one of my new favorite words: sexagesimal. ;)
"Mathematicians in the Arab/Islamic world employed the system of Indian reckoning (al-hisab al-hindi), using nine figures and a zero (indicating a vacant place) as the basis for calculations in a decimal place-value system of numeration, or positional notation [i.e. tens place, hundreds-place, etc.]... Though the ancient Mesopotamian system was decimal, fractions were often expressed in the sexagesimal system (based on the number 60), so 1/2 was 30 parts of 1 (30/60). Ptolemy used the decimal system for whole numbers and wrote fractions (hence minutes and seconds) in the sexagesimal system, which Greek astronomers had adopted from the Babylonians. We still use the sexagesimal system for time, where a fraction of an hour is 1/60, and so on, as well as for angles and degrees of a circle." Kraemer, Maimonides (2008: New York), p. 67.
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