I'm trying to understand how to "use" these books (BFSU,etc). I see that in the first one that it is 41 lesson plans for K-2. Is it really K-2, or could an older child use it? Also, do you use supplemental reading materials? Are these assigned in the book, or are they of your own choosing? Could you jump into the next level (I forget the name), without ever having done the first level? Is this a complete curriculum? I'm totally confused and rambling. I am a scientist, and have never found a curriculum that meshed well with us. If anyone uses this, could you please, please tell me what/how??