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/
*Puts on glasses* Akchually, that's only if you're counting 10's, since we count 1's as decimal and 10's in pairs of snes/snaes (20), hence fifty is half three snes or 3*20-0.5*20 = (3-0.5)*20 = 50.
Or if you're talking 1's, aka. decimal, you'd just remove the snes part, since common math is in decimal anyway, so half 3 decimal would be 3*1-0.5*1 = 3-0.5 = 2.5.
EDIT: Fun fact: 100, aka. "en hundrede/one hundred", can therefore also be called "fems" or "fem snes/five snaes". And then there's the ones who actually say "in twenty" instead of "snes", so it'd be "fem i tyvende".