Title text:
Other numbers are largely unaffected, but anyone using '4' for their certificate key is urged to upgrade to '5'.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3314/
this post was submitted on 21 Oct 2026
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Well, it is just arithmetics.
The left side of the equation is just the natural expansion of the paranthesis to signify and drive home the point that we're specifically talking half off 20.
The middle is how it's usually represented and follows best practices. Aka. Simplifying the equation without touching the variables and constants.
The right side is the result for calculating the equation.
I'm unsure of any tutorials regarding the danish counting system, though there's bound to be some. :)
Did I misunderstand the question?