• WanderingThoughts@europe.pub
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    23 hours ago

    IIRC they counted the bones in their fingers using their thumb and that gives 12. The first sundial was around the equator and there is always light for half a day, so half a day becomes 12 hours.

    To count large numbers often one hand was used to count using 5 fingers and the other to count the bones, so you get 5x12 for 60 minutes.

    • WolfLink@sh.itjust.works
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      21 hours ago

      AIUI there was an aspect in the divisibility of the numbers being convenient.

      12 is divisible by 2, 3, 4, and 6. 60 is divisible by 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30.

      10 is divisible by 2 and 5. 100 is divisible by 2, 4, 5, 10, 20, 25, and 50.

      If you want to minimize dealing with fractions, 12 and 60 are far more convenient than 10 and 100.

      • WhatsTheHoldup@lemmy.ml
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        20 hours ago

        That’s an interesting thought, but I believe it to simply be a coincidence.

        The base 12 counting being based on counting the division of your fingers is historically verified, but if the division aspect was so compelling to them you’d expect it to carry forward into their writing system.

        By the time you get cuneiform math though, they actually go back to base 10.

        https://images.app.goo.gl/9GR6VEiT7GHYF3KaA

        As you can see base 12 is not in the written system, or for written mathematics. It just was convenient for counting on their hands.

        They used mixes of base 10/base 12 and base 60.

        Base 10 would be used go determine the symbols for a specific “digit” in base 60.

        So similar to how our 13 is 1 ten and 3 ones, their 13 was the symbol for 10 then 3 symbols for 1. 13 = 𒌋𒁹𒁹𒁹 But 73 would be written 𒁹 𒌋𒁹𒁹𒁹

        Which would be interpreted as 1 sixty and 13 ones, or 60 + 13