>>/3416/
I dunno, pretty much everything.
A trivial example would be factoring 429, like just from the beginning adding the numbers together I go automatically native instead of "four plus two, plus nine" to establish divisibility by 3.
Even just going "four plus two" I cannot imagine thinking "six" as an answer, if I see the numbers I go through my native (so 4+2=6 then "six")
There's just strong association between the concept of numbers and the names in my native while it just doesn't exist in english because I never calculate stuff in english and I have a hard time even making myself do it because of that lack of association.