Yeah, it's easy for you since you grew up with that system, but as an expat in Germany it is a monumental pain when someone is dictating you long numbers (telephone, social security, insurance, etc.) in groups of two over the phone and you gotta scribble them quickly on a piece of paper since you tend to write the first digit you hear, but that's actually the last of the pair you gotta write so numbers get easily mixed up.

Example, dictating and writing down 23.45.67.89 in pairs over the phone, would sound like "3 ... and twenty", "5 ... and fourty", "7 ... and sixty", "9 ... and eighty" which is difficult to not fuck up and swap them when under pressure of writing quickly, if you don't count the same in your own language/culture, and you haven't agreed over the endinanness with the other party before the dictation starts.

So you're left with 2 choices if the other party uses this system, either you write the first digit you hear, which is actually the last, and leave a blank space in front, so you can write the "x_ties" number when it comes up, but that only works on paper but not on a dialing pad or keyboard as the cursor keeps moving too the right, or, the other option, you wait to hear each number pair before you start writing them down, then you start writing, but that can also causes mixups in your brain during the decoding of the reverse order from hearing to writing if the other party dictates the pairs quickly.

Or, you just throw in the towel and ask the other party to dictate it digit by digit and call it a day.

So, apologies, as I have to disagree with you. It may work well if you're counting incrementally to keep track of something, but for transferring non-sequential numbers over the phone, this is a stupid numbering system that causes more problems than it solves.

In theory, yes, yet my adult brain cannot process correctly decoding this reversed order quickly, under pressure, over the phone in writing, even though I learned to be fluent in German. I guess you have to grow up with this system so it imprints on your subconscious from an early age, else, if you grow up with another system, and need to switch later in life, it's game over.

Learning this number system is easy, but under pressure over the phone, this reverse pair system falls apart quickly as you tend to write the first digit you hear instead of waiting for the full pair, which is why it's not used in military/critical radio transmissions, because it opens the gates to many errors and proves the system is broken for anything else than casual private use.

Every once in a while I say a number backwards (like once or twice a year), but I usually catch myself half-way after spitting it out.

I will say that even an adult brain can adapt to foreign ways. It does get easier, though in the process you lose something of your original language.

Except it doesn't work well, as proved by the fact that this system is not used in the military since even top comment in this thread where a German agrees that even he gets confused by numbers in pairs over the telephone and as proven by the fact that Norway transitioned from the "German" way to the "English" way precisely to fix this issue.

I see you're very defensive about your culture/way of doing things, but just because some linguistical quirks exist to date in some languages, is in no way poof that they are good or that it works well, it's just proof that inertia is very strong as these issues get grandfathered in over time since transitioning to something better is too expensive for entire countries to make (look at why the imperial system is still used even though it's inferior to metric).

And for some countries/cultures, introducing certain linguistical quirks on purpose and keeping them was, and still is, a matter of national pride and differentiation between their culture and other very similar cultures (see French vs Belgian French vs Canadian French vs Swiss French, or German vs Austrian German vs Swiss German), so changing something for the better would be admitting something was wrong all along in their culture and would definitely face backlash from conservatives and purists, though Norway did the change successfully from the "German" way to the "English" way of speaking pairs of numbers in order to fix the confusion issues I mentioned.

English has decided to use single words up to 20. Other European languages stop at 100. Both are arbitrary and right or wrong in their own way.

The English word would be "five and forty" because "fiveforty" would probably mean 200 going by traditional English (in the same say "four score and seven" means 4*20+7, not 24+7).

Somewhat reminds me of typical hexdump representation, where even if data has little-endian bytes, nibbles inside each byte are still ordered big-endian.