I sometimes describe DS7 as "mathematically precocious"; I like this because it acknowledges, for example, that what can be known now is that he's ahead of age peers now, not that he will eventually outperform them. I dislike the "gifted" label and "able" (which is the official term where I am) isn't much better - both seem to buy into the entity theory of ability and I'd rather not have my language implying that I do! (What I actually think is that it's complicated.) That said, most of the time I find it possible and preferable just to avoid set phrases altogether and describe whatever aspect of reality is relevant right then, e.g. "he needs more practise at problem-solving in maths" or "he's read a lot about [topic]".
