Seems like DeeDee's idea is good.
How is the math text's quality? If it's anything like the 4th grade math book my DD is using, the word problems are often really terrible. My DD has zero problems with anything computational, but she gets some word problems wrong. When I look at them, I know why. I don't know what the hell they mean, either. Her text is also heavily reliant on a lot of artificial vocabulary and rules that are slow and frustrating for an inherently mathy kid who can look at the problem and see the answer without doing any of that.
That's what I was wondering, as well.
Assessment which becomes more about the tool than what it purports to evaluate is a HUGE problem for us. It's always been the single biggest problem across all subject areas, in fact.
What has school taught my DD?
a) how to write coherently at a level roughly meeting expectations for a bright high schooler, and
b) how to assess the mind of a test-writer so as to attempt to parse the poor communication efforts of others.
That's it, pretty much. While I think that both things are good to learn, I'd obviously have preferred a lot less emphasis on the latter point. It seems grossly unfair to me that to meet the needs of non-NT kids, they have to be BETTER than the adults providing them curriculum and instruction at communication just so that they aren't improperly labeled/categorized. Honestly, that'd be a pretty tall order even for many adults.
"Ohhhh, see, and with THIS question, you were supposed to assume that _________________. Not like that other question, where you weren't supposed to know anything at all that you haven't learned from the class textbook, I guess..." 
Drives me batty.
What happens when she tackles something like Singapore's Challenging Word problems workbook, Val? My DD loved those problems when she was this age. I couldn't get her to willingly work on drill, but she loved the mental challenge of tackling something she could sink her teeth into like that. (That's still more or less true, actually.) Well-written/slightly snarky word problems seem to go over better with GT kids because there is an intrinsic reward in doing them.
