This book can be used by 5th to 8th grade students preparing for AMC 8. Each chapter consists of (1) basic skill and knowledge section with plenty of examples, (2) about 30 exercise problems, and (3) detailed solutions to all problems.
Volume 3: http: //www.amazon.com/American-Mathematics-Competitions-Preparation-Volume/dp/1501040553
Volume 4:
http: //www.amazon.com/American-Mathematics-Competitions-Preparation-Volume/dp/1501040561
Volume 5
www.amazon.com/American-Mathematics-Competitions-AMC-Preparation/dp/1503019705/
Volume 6:
http: //www.amazon.com/American-Mathematics-Competitions-AMC-Preparation/dp/1507544162