My DS6 just started EPGY math from Stanford about 6 weeks ago and he loves it! It does seem dry, but it moves quickly and mixes it up enough to make it more interesting. We started him at Grade 1 to make sure there were not any gaps and he has progressed to Grade 2.5 already. It's $95 for 5 months to try it out. He started out doing 20 minute sessions, but asked for more so we had the administrator up it to 30 minutes. There are also two setting to be aware of, regular and gifted. You can have the administrator set it for gifted from the start. It moves at a quicker pace. You can also up the level yourself by 1/2 grade increments if it's too easy for him. It also tracks, in detail, what grade equivalent, topics covered, percent correct, how he did on a particular session day, etc.
I would think it would be easy for him to do this at school as long as he knows how to log in to his account. My son's principal was working on having him do this at school too, but that's a whole other story,
His K teacher would not supplement of give him more challenging math so we resorted to giving it to him at home. He's so happy to be doing something other than adding 2+2 and then drawing picture after picture on a worksheet for simple addition that it was totally worth it!
On a side note he just started the Language Arts component of EPGY and loves it too! It sounds like your son is a big reader so he might enjoy that too!
