By the time you're in a restaurant figuring out tips you've already forgotten the handwritten long division algorithm - and probably don't give a fuck if it's exactly 10 percent or whatever.
and I mean, fuck, must have spent basically 100 hours of schooling on that in one way or another(calculators were banned in finland in schooling in my schools for quite late, up to upper elementary school). they could have taught us something different with that time. geometric optimization(not sure if correct translated term) earlier or something.
oh and in Finland - YOU DON'T NEED TO CALCULATE TIPS. the salary of the waitress is in the food prices as is the tax included in the menu prices. furthermore, every restaurant will keep one bill per one person in the group unless you want otherwise(by default, 5 people go into a restaurant, if they not mention otherwise, each will get their own bill and they only what is on the bill).
if for some reason someone wants to pay part of dinner for someone... then he/she is likely to just pay it all - and even then, maybe just for one other person in the group. if someone is particularly generous he might pay the whole thing, but that practically never happens with common people(and the rich too for most part in Finland act like common people).
for some reason this is no trouble at all for finnish waitresses and I always feel like a victim of some sort of shitty marketing ploy or bait and switch when eating abroad and the prices don't include the expected tip to waitress(fucking tax evasioners). some places even have "tax % and service charge %" , if they have that, why the fuck not include it in the prices on the fucking menu? if some law doesn't allow that or using similar excuse, simple enough to put the two prices there.
also in Finland, if you go to a grocery store - you look a price and that is the price! no bullshit like adding the tax at the till - also haggling generally happens only in business-to-business sales, there the margins and haggling can be brutal - used car sales are another exception. business to business advertised sales prices also generally have two prices on them, with VAT included and not included.
your use cases: nobody uses handwritten long divisioning for those.
as for using calculators, you still need to know how to use them and be able to figure out in your head if the result makes any sense whatsoever. I'm spending my second year in Thailand and... well, let's just say that Thai education seems more fixated on patriotism than on teaching kids if correct change for 1000 for an item that cost 450 is 450 or 550 - you would think that someone who makes 400 of said monetary unit per day would care about the 100.
(*finnish bureaucracy though is pretty brutal for companies. however, there's generally no bullshit hidden bribes involved either)
as for cursive/script. they played around with it already in the '90s - for example the script that was taught to my brother drew some letters differently than the version that was taught to me. the highschool final exams were pretty much the only place where it was compulsory to write with it(the 2-4 page essays). but here's the bit: fucking hard to read anyone else's script, good or not. if this makes them focus more on the content of the text and grammar then all the better.
Finnish grammar and words are another peculiar thing, since they keep revising it almost every year - some slang words get promoted to acceptable by the language office(tm)(r)(c) - so, one year lose points the next year not for using a particular word of phrase.