I don't know. My son likes Dragon Box and the HOE app too, but I don't think he's even close to being ready for algebra. I want to echo what the others have said here. My highest priority, in tandem with giving my son a rigorous, liberal education, is to teach him grit. I was in G&T programs growing up, was accelerated a grade, and basically coasted through school with easy As in "hard" classes until I got to law school. When I was finally challenged in a meaningful way, I was in my mid 20s and had developed a terrible perfectionist streak. Law school was a terrible time for me because I didn't have the emotional grit to deal with educational adversity in any serious way. Granted, I was lucky to have gone to a good enough law school that my (mediocre) grades didn't have a huge bearing on my marketability. But working 80-100 hour work weeks, in ridiculously competitive industries, being smart just wasn't enough. I sure wished then that I had learned to be comfortable with struggling. I want my son to struggle early and often, not to the point of debilitating or damaging him, and most certainly in an emotionally secure and loving environment, so that he learns the valuable life lesson that I experienced far too late.