I should clarify - when I say too much language, I am not talking about word problems. Real word problems are awesome, and AoPS is replete with them. The kind of contest math DS loves is almost all word problems (and visual puzzles - yeah!). Do trust your own experience with your DS, and don't let math education experts (let alone the likes of me) undermine your confidence in your own judgement. FYI, I've seen tons of positive feedback about Singapore math on this forum; it is a great exception to the type of curriculum I am describing. And I'm always bugging DS not to do too many steps in his head, so that he can see where he's made a mistake. So totally agree with you.

What I'm talking about instead is taking the math out of math (so it's not scary any more), and turning it into a language arts activity. 20 pages of worksheets where each page has one or two basic calculations, and you must spend the rest of the page on at least six sentences per calculation describing how you did the addition (and then of course write out your answer in a full sentence). Write your own 1-page math story. Endlessly. The kids might spend 1 minute on something vaguely mathematical (basic, repetitious calculation that it is) for every hour of paragraph and essay writing.

This is how my writing-disabled math monster came to think of himself as bad at math. Unquestionably, he couldn't do the tasks assigned in math class.

I'm also not talking about showing your work where there is actual work to show. Again, we have lived the deep contrast between our curriculum and AoPS. The on-line AoPS course required a detailed, full sentences, explain how you got your answer proof every week. BUT - you were dealing with a problem of sufficient complexity that there was work to show and thinking processes to explain. DS actually enjoyed creating these proofs, even though they tended to take around a full type-written page each. They challenged him to articulate - and back up - his mathematical thinking, coherently. This is a very important skill (and my impression is Singapore math does this pretty well).

Hope this helps.