I had someone tell me recently that one of the best things you can do for your kids to help them do well in math is to tell them that they are good at math. I, personally, have never been very good at math. I've "known" that my whole life, but I'm not sure when it started.
My Mr. and I count with our 3-year-old and I've started telling him how good he is at counting and how he's good at math. My 5-year-old likes to work out addition and subtraction problems for fun, so we do that, and I compliment him on his math skills. I guess the idea behind the "you're good at math" compliments is that really, until they are in high school, there is no reason for any child to be "bad" at math, and that if young kids are told that they are good at math, they will be.
My 5-year-old (who is very good at math) has been getting a little bored with the adding and subtracting, so we've started algebra. :)
Things like that. He thinks it's pretty cool, and I'm afraid that my child-who-is-good-at-math will soon be better at it then I am (I guess I'd better start studying).
Next we're going to talk about story problems.