Thanks for the suggestions one and all.
He is engaged and excited to get a new concept, but when he tests or does an assessment, he scores in the 70 percentile.
He has a level equivalent book that has most topics included which has helped a bit.
I do believe that he is struggling with some of the "foundation" ideas and concepts so I am very concerned that unless he gets a hold of this, he will continue to tread water, be frustrated, and hate math.