1900 BC |
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| The decimal system with which we are fated is a place-value system, which means that the value of a particular digit depends both on the digit itself and on its position within the number. For example, a four in the right-hand column simply means four ...... in the next column it means forty ...... one more column over means four-hundred ...... then four thousand, and so on. | For many arithmetic operations, the use of a number system whose base is wholly divisible by many numbers, especially the smaller values, conveys certain advantages. And so we come to the Babylonians, who were famous for their astrological observations and calculations, and who used a sexagesimal (base-60) numbering system (see also The invention of the abacus). | |
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| Although sixty may appear to be a large value to have as a base, it does convey certain advantages. Sixty is the smallest number that can be wholly divided by two, three, four, five, and six ...... and of course it can also be divided by ten, fifteen, twenty, and thirty. In addition to using base sixty, the Babylonians also made use six and ten as sub-bases. | ||
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| The Babylonian's sexagesimal system, which first appeared around 1900 to 1800 BC, is also credited as being the first known place-value number system, in which the value of a particular digit depends both on the digit itself and its position within the number. This was an extremely important development, because prior to place-value systems people were obliged to use different symbols to represent different powers of a base, and having unique symbols for ten, one-hundred, one thousand, and so forth makes even rudimentary calculations very difficult to perform (see also The Ancient Egyptians). | Finally, although the Babylonian's sexagesimal system may seem unwieldy to us, one cannot help but feel that it was an improvement on the Sumerians who came before them. The Sumerians had three distinct counting systems to keep track of land, produce, and animals, and they used a completely different set of symbols for each system! |
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| These notes are abstracted from the book Bebop BYTES Back (An Unconventional Guide to Computers) Copyright Information |
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