This is part of a guest lecture that legendary mathematician, John Conway, gave at UC Berkley in 2012. I thought it was a goofy aside that could be understoo...
    • threelonmusketeersOPEnglish
      3·
      3 hours ago

      21 should be

      2 + 1 = 3, therefore 21 is divisible by 3 and is not prime. QED :)

      • BigDanishGuyEnglish
        21·
        2 hours ago

        9+1 = 10, therefore 91 is divisible by 10 and is not a prime … QED, I guess