This is a copy of a post from my other blog:
We love Singapore math. I started my first on Saxon and we both hated it for the constant repetition and it's sooooo dry. The Singapore books are like you're playing. If you did have your kids go back, they'd probably actually enjoy it it because there are so many codes and mazes and things to , so if they already know the concepts it would be a fun review and practice but you can have them take the placement tests on the Singapore site to see where they are.
I have posted a couple posts on our math experience on my blog if you want to read about it. My first daughter had a bit of a hard time transitioning and we took a loooong time on levels 1 and 2, finally by level 3 I decided we needed to really focus on math and get her caught up. Level 4 was tough, but now she's onto level 5 and whizzing through. I'll find out tomorrow how well when she takes her test which is the placement test on their site. I'm hoping she'll start Algebra by the end of this year, she'll be 6th grade age.
It was a tough transition I think mostly because she got a sour taste for math from the boring Saxon books, and she's more of an artsy imaginative kid not real math minded. The other kids who started with Singapore have just whizzed through with no problem. They slow down when we get to a harder section, but once they get it, they're off. They should be fully prepared to start Algebra when they finish level 6, and the story problems are amazing. I'm learning how to solve them without Algebra. Then we plan to use the Algebra and Geometry books from McDougall Littell. We haven't picked the Trig or Calculus books yet.
Also the US edition Singapore math books are the ones they were using in their schools when they were ranked #1 in the world for math. Tried and tested with excellent results. Love it!!! Good luck on your decision.