Hands on Equations has webcasts and do some give aways.

I think Beast Academy is by the Art of Problem Solving folks, and for some reason I think they are comic book style. I don't know much about either one. I just know they are the current darlings of a lot of folks on those boards.

Greta Lea, I realize these may be way beneath your ds's level, so I hope (and I prayed before posting this) that I do not offend you by even mentiooing these. I just am tossing out ideas to help find the key to unlock this in your ds's mind.

(((Great Ale))) and, no, that os not a typo! ;)