I am no expert. We are just starting our homeschool adventure tomorrow with my DD8. I bought the 3A and 3B books used without anything else because I wanted to start her officially in 4A. She worked through the 3A but it was mostly new to her, but when I sat down with her on the 3B, she had learned most of it. So, I decided we would do a 2 weeks of the 3B that she had learned as a quick review just to make sure she hadnt forgotten it and I matched the rest of 3B that she hadn't learned with the 4A topics. I will do the 3B explanations and a problem or two to introduce the topic, but then just go straight to the 4A book. If your daughter is very good at Math, an approach like that should be no problem. I got the books used at our local Homeschool Store. So, buying the extra book to fill in the gaps wasnt too much.
