Individuals can purchase McGraw Hill math book answer keys. Answer key books are available by individual grade level.
Some websites, such as Abe Books, sell used versions of McGraw Hill math answer keys. This website has grade 1 answer keys in good condition as of 2015; they were published in 2003. The book is sold by various sellers through Abe Books.
Used copies in good condition as well as new copies of the grade 5 answer book are available from Amazon. This book has 155 pages and was published in 2005. As with Abe Books, third-party sellers sell their copies of this book through Amazon.