Strong program with emphasis on deep understanding of concepts and love of math. Would highly recommend above most curriculums I have tried.
The K-5 program is strong and could easily be used in any k-6 program. The content is challenging but so strongly done that any level of student could use the program with support.
The art of problem solving program for 6-12 is very challenging. It could be used for all students, but again, would need support. The online classes are excellent, books alone would need strong classroom support. Clearly aimed at high functioning students. This is a math program that goes beyond basic understanding and rote memorization to emphasize true, deep understanding and complex thinking. There are a plethora of problems available and a rich online community.
How I Use It
I have used the Beast Academy Series for my kids when they were younger, then they have transitioned into the Art of Problem Solving for 6/7-12. If kids start with Beast Academy at a younger age I think they could be successful in later classes. Beast Academy starts with Grade 2, then goes through 5, though they cover more than most curriculums.