I use both BJ and Math-U-See. The way I see it is, it works for us. I also use printables to reinforce what the books lack.
We have always used supplements. Saxon and CalcuLadders mostly, the drills in my opinion, are necessary. I've never purchased 2 complete programs though. We are switching to Teaching Textbooks next year, so I'll wait and see if we need to do anything else.
I picked up this great book at the library yesterday to hopefully try and make math a bit more fun and less stressfull for her. It is full of number games and riddles. We are going to try it today. She is also continueing with MUS today. The last two lessons she did much better and didn't stress so much. At this rate we may not have to do math all summer to finish the book afterall. I hope she keeps it up.
the candy coated chocolate candies ! MY favorite! I used them for many math needs! THey have been fractioned off , sorted, multiplied and divided, though as you get to larger numbers you have to use a bigger bag, but the attentiveness they have knowing that when they are done they may get to eat some of them is amazing! There is even a book called M&M Math, it says M n M on the candy though hehe
For Math, I'll supplement with some extra worksheets if she needs more practice. We also play Math games to help with review (she hates to review, so I try to make it fun). I would never use 2 full programs, though.