An answer key for Go Math problems is in the chapter resources section of the Teacher Edition. Teacher editions assist teachers in meeting the Common Core standard. Each chapter focuses on the process behind the math so that students seek more than simply arriving at the right answer.
Go Math is published by Houghton Mifflin Harcourt and is one of the standard teaching aids for ages K-6. This series is available in print, and teachers, parents and students have access to the same material in an interactive online resource. The Go Math series contains additional resources for specific middle school and high school math concepts.