Author james cross giblin’s purpose for writing the riddle of the rosetta stone is to inform readers about how scholars built on each other’s knowledge to decipher the rosetta stone and learn about egyptian history. explain to readers how hieroglyphic writing is similar to other languages using specific examples. persuade readers that champollion was the most important of all the scholars who worked on deciphering the rosetta stone. entertain readers with an adventure story about scholars traveling through egypt and making fascinating discoveries.