Thanks for the feedback, and especially for the welcome. I do feel like I'm pulling my hair out, and it's good to have some support.

I think Kriston's comment about his picking up on ambivalence is important. I try hard to express equal enthusiasm when he hits the ball and when he discovers some new math fact; DW does too. Indeed, I think we both genuinely feel equally enthusiastic about these. But I think DS has learned that not everyone treats these skills equally. And frankly, the broader environment affects us too: I myself find it hard to talk about math with DS, for instance, when others are around. People just look at us funny. Does anyone else have this problem?

By the way, I discovered the finger trick for nines myself just this morning; I can't wait to show it to him!

BBDad