The book, “Crossmatics: A Challenging Collection of Cross-Number Puzzles,” containing math puzzles and solutions, is no longer published and is not available from Dale Seymour Publications, which is now part of the Pearson Learning Group. Contact the latter for further information on how to obtain the Crossmatics answer key.
From the Pearson home page, click the Contact icon towards the top of the page. Click Contact Customer Service, then click the Customer Service tab. Contact options, including email, phone and online chat, are listed near the bottom of the page. Select your preferred method of communication for detailed contact information.