Obviously language changes, which is the reason why numbers have many different names in languages. Comparing the German "einundzwanzig" (one-and-twenty) with the English "twenty one" shows what I mean.
My question is about changes that happened naturally and without influence of another language. I got curious in this because, if math is offered in a public school, then a child gets to know the numbers by the name of their language. It gets ingrained into them and thus it doesn't make sense for an adult to suddenly change the word for a number and even less sense for a school to do the same.
Is there any language which has undergone such a change since the introduction of public schools?
If there are indeed such languages, how could they undergo such a change?