My mathy kids love pattern blocks, plastic or wooden shapes in a big bucket. Here's an example:
http://www.didax.com/shop/productde...c/StartRow/1/ShowAll/No/ItemNo/2-483.cfmThey're obviously good for geometry and fractals, but they are also good for arithmetic practice, (especially multiplication), fractions...and art!
I'm sure there are many other uses. And they're more exploratory and hands-on than much of in-school math. (At least what we experienced.)
Also in the geometry area, we liked "Painless Geometry," by Lynette Long. It's simplified without being dumbed down. It is more of a real curriculum though, so it may not work for you.
There are also some hands-on algebra sets, though we haven't used the one I bought yet so I can't vouch for them as I can the pattern blocks. Something like this:
http://www.didax.com/shop/productde...c/StartRow/1/ShowAll/No/ItemNo/2-487.cfm(Though you might just search "algebra" on the Didax or similar site and find other things you might prefer. I just linked to the first one I saw!)
I like the idea of teaching math concepts in hands-on, experiential ways that are very child-led. I think it cuts down on the risk of doing it "wrong," since you're doing it completely differently. Plus it's more fun for the child and should help connections to be made as they mature.
FWIW...
