DS is using EPGY math at school (at our expense, through melmichigan's homeshcool "district"). The other "highly capable" students in the class are getting math enrichment with "Larson Math", which I think is also called (or has been bought out by) "iSucceed Math". I don't know much about it, but I think it is designed as much to help remedial students as it is to enrich gifted students. I don't know whether it will actually allow students to accelerate beyond their grade level or not.