(Of course, you can also simulate that experience by drilling this for ten minutes a day until it becomes second nature.)
I do find however that it also depends on "when the number was remembered". For example, relatives phone numbers I remember in my head in non-English, as I learned them in that language. But my credit card number I recite in my head in English in order to write it out on order forms.
And numbers for calculating and such for a very long time was still non-English but I think it's habit. In my head, nobody tells me "Sorry dude, what language is that? I can't understand a word" and so there's never any real incentive. It's also faster to do that part in your first language and only say the result out loud while thinking about words (especially entire sentences) in your first language and then translating and saying it in English makes for awkwardly long pauses or really bad sentence structure. I think that provides again more incentive to learn English sentence structure and to think in English to begin with, so that words come out "right away" as you think and formulate.
Technically Hindi would be my mother tongue, but I wonder how all that plays out in terms of having initially been raised with it, then having entirely forgotten it and replaced with native level English for a few years, and then having relearned Hindi from scratch. I tend to think in a mix of both languages, and have a tendency to mix words from other languages into my thoughts too if I'm exposed to them often, even if I can barely speak those languages.
I can’t even describe the absolute weirdness of saying “I love you” to my wife after building our relationship over years in only. Spanish. There is definitely some kind of personality disconnect when I learn language and culture by immersion as an adult.
And yes, numbers are problematic. Spanish me really, really, really sucks at math. Even trying to do basic subtraction or calculate a trivial tip ends up with internal translations to work out.
As a bizarre aside, Once in a while I can be nudged into a temporary unresponsive state by the right timing of a language change by my speaking partner.
When I “snap out of it” it’s like the words went into a que but nobody fetched them so I went into some kind of waiting condition. It’s really weird and makes me wonder if there might not be a lot of ways to trigger altered states through similar hacks.
I use English mostly (and am certainly a native English speaker), but use my mother tongue to memorize numbers, as mine (Cantonese) has single syllable numbers. I think I can keep 5-7 numbers in short-term memory in english, whereas I think it's closer to 10 or 12 in Cantonese.
I'd say I speak better my adopted tongue than my native one. People from my country say I speak with an accent, while locals are surprised to learn I'm a foreigner, since I speak with no accent. When I think about things, I also use my adopted language (I went to school here, so it's easier, since I've learned the concepts in this language). Hell, I sometimes use English for my internal thinking. Just not when counting or adjacent tasks.
He specifically talks about this! Apparently the spoken word, the written word, song lyrics, and numbers are all processed in different parts of the brain almost as if they were different languages. He even mentions the same phenomenon as you and I think he also said this is the first part that gets hardwired into your brain as a kid, leaving you stuck counting in your mother tongue forever.
https://en.wikipedia.org/wiki/Traiskirchen#Refugee_Camp_(Bun...
https://en.m.wikipedia.org/wiki/LOT_Polish_Airlines_Flight_1...
Two days ago I was jump roping. Sometimes I was (mentally) counting in English, sometimes in my native language. I'm not sure which one I did more often, but when I paid attention, I noticed that I made fewer mistakes when counting in my native language. An explanation would be that my brain can do that more effortlessly. Despite the fact that I lived in the US for longer than I lived in my native country.
I'm not sure if it's related but a similar thing happens with spelling. I guess because there's some ordinal relation to the letters in a word? But I feel whenever I need to spell my name in English it takes me about the same mental effort as giving my phone number, and I'm otherwise rather fluent in that language.
I count and do all my numbers in English, UNLESS I am in The Netherlands and I have just been talking Dutch then I do it in Dutch. I do not switch to Dutch even internally for my internal monologue when I encounter numbers.
I agree, the one thing I tend to still do literal translations in my head for is for numbers and arithmetic. Its just so much more cumbersome mentally for some reason to do the math in my non-native language.
Consider e.g. the number 157. That'd be 100 + 7 + ((-0,5 + 3) x 20), only that they don't pronounce the "x 20" because then it is too long.
I still can't count in English.