The author, Dr. David Ward, is a physicist, educator, home-school parent, and entrepreneur. He received his PhD from MIT and was a post-doctoral fellow at Harvard University. He has publications in Nature, Physical Review Letters, and the Physics Teacher, to name a few. The characters in "Sarah and Sam Save the School with Even Numbers," are based on characters from the martian mathematics curriculum used by homeschoolers. He originally developed the curriculum for his own children, but it is now available to the public at MartianMathematics.com.