That reminds me, I genuinely have a hard time doing any significant math in english. 
I've done maths in native my whole life and it just does not compute for me because the association between the number names in english and the concepts of those numbers seem to be rather nebulous for me.
Like I can read and write them just fine, but whenever I need to do any number manipulation I read them in my native, calculate, then translate back to english if needed.