• glibg10b@lemmy.ml
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    1 year ago

    Explanation:

    In decimal (DEC), we count to 9 before adding a new digit. For example, the number after 9 is 10, and the number after 19 is 20.

    In octal (OCT), we count to 7 before adding a new digit. The number after 7 is 10 and the number after 17 is 20.

    DEC OCT
    0 0
    1 1
    2 2
    3 3
    4 4
    5 5
    6 6
    7 7
    8 10
    9 11
    10 12
    11 13
    12 14
    13 15
    14 16
    15 17
    16 20
    17 21
    18 22
    19 23
    20 24
    21 25
    22 26
    23 27
    24 30
    25 31
    • kylostillreigns@lemmy.world
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      1 year ago

      TLDR: In octal system, the weight of the digit in a position is an exponent of 8. So 31 = (3×8¹ + 1×8⁰) = (3×8 + 1×1) = 24 + 1 = 25.

          • glibg10b@lemmy.ml
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            1 year ago

            Sure, it’s shorter, but is it really a summary of my comment, or just a more technical explanation?

            My comment tries to teach via example, while theirs tries to teach using math. I chose my method because it’s the most accessible to people who aren’t math-inclined, but also because it takes the least cognitive effort to understand, which is an important quality for a social media comment to have nowadays.

            Besides, you obviously don’t have to read the whole table (you already know how to count to 25). Just scan the right column to see what it’s doing differently.