As a kid, I still remember the day that my dad was helping me with my Maths homework. On one tricky problem, he unconsciously started muttering the numbers out

As a kid, I still remember the day that my dad was helping me with my Maths homework. On one tricky problem, he unconsciously started muttering the numbers out loud, and I was surprised to hear him saying them in Tamil (he is from Sri Lanka, but we spoke only English at home as far as I've known). I asked him about it later, and he said that in his head, he always translated the numbers or problems into Tamil, solved them, then translated back to English to present the solution - because he was taught maths as a kid in Tamil. He could still do all that faster than I could in all English!