Although it's not as well-known here, a few of us have used curricula from The Math Learning Center. There are various program titles depending on the level. My greatest experience is with Bridges (a new,
K-5 curricula) and Opening Eyes (gr. 3 & 4.) I used Opening Eyes when I taught public school and loved it so much that I went looking for MLC curricula when I decided to homeschool. I now use Bridges and love it!
It's a very hands-on, constructivist curricula with lots of games, real situations, etc.... I just finished teaching a Bridges unit on probability to a group of 9-13yos and they had a blast! :)
Cynthia