Maria at Homeschool Math Blog has posted a fun set of worksheets:
Pan balance problems to teach algebraic reasoning.
Princess Kitten, at nearly 9yo, keeps telling me, “I hate math, but I like algebra.” So I printed all four pages for her to try. These get pretty complicated, and the 2-variable problems had her flummoxed for awhile. But after an explanation and bit of pouting (I think she hates math because she’s such a perfectionist that she can’t bear to get something wrong, even the first time), she came back and conquered the toughest ones.
Denise Gaskins' Let's Play Math 
Thanks. My 6yo will love these. It’s getting quite hard to find things to challenge her (she leans over my shoulder while I’m trying to do sudoku and tells me where the numbers should go,… and regularly beats me at checkers).
…and she loved them. I gave her page 1, which lasted her a couple of minutes. I don’t want to push her at all (I want mathematics to stay as just something she does for fun), so I think I’ll leave the rest for now – but the blank sheet will be handy when she feels like more.
I’m glad your daughter had fun with these puzzles. She sounds like a bright young lady!
http://www.education.com has some great Sudoku puzzles for kids! They start with only numbers 1-4, and go all the way up to the normal 1-9. The kids in my class LOVE them.
You can try also http://www.jumpstart.com/parents/worksheets/math-worksheets to know more about math. You will find for all graders.