Mark, the little Minus Sign In the sweetest book that ever was written about math, Mark, the little Minus Sign, is on the adventure of a lifetime-and the story problems he solves are just the half of it. He's also learning about growing up: making friends and finding his own unique talents. The youngest of readers, ages four to six, will love the story of Mark who is not so different from them-which will help prepare them for encountering their world and the world of math. Older readers, ages seven to nine, will thrive on the "mirror writing" in the vibrant illustrations-this writing is like a secret language that shows thoughtful messages meant to inspire; the cipher to be deciphered is a cool bonus. All kids will delight in the surprise at the bottom of each page-flip the pages like a flip book and see the adorable little animation come to life. Even adults will enjoy the story for its math concepts and humor. For example, readers learn about the order of operations: "Taking care of what is inside the parentheses first" is what Mark's parents do. They are each a "parenthesis," surrounding Mark with love. Taking care of him is their first priority. Math can be a big unknown factor to many, but by enjoying Mark's adventures, the world of math-and the world in general-won't seem so scary after all.