This hardcover is an ex-library copy with all the usual markings (stamps, stickers, library marks). There is some shelf wear on the corners and edges with a name written on the inside cover. The library binding is tight and pages are clean. 📚 Check out my shop for more A Young Math Book, mathematics, vintage, & living books! Synopsis | When the kids in the neighborhood lay out a baseball diamond, or when they are instructed to fold their papers "into three equal parts, for spelling," they are using the principles of STRAIGHT LINES, PARALLEL LINES, PERPENDICULAR LINES. The lives and livelihoods of printers, architects, painters, builders, and many others, in addition to mathematicians, depend on these principles, too. In this charming book, Mannis Charosh has asked the young reader to imagine a world without rules or straightedges. To make a straight line in such a world, all you need is a piece of string. If, in addition to the string, you have (or make) a checkerboard and checkers, you are well equipped to explore the world of straight, parallel, and perpendicular lines. If you do all of the experiments and activities in the book, you'll be able to recognize such lines with the greatest of ease. Enrico Arno's bright straight, parallel, and perpendicular illustrations enrich and enhance this fascinating and informative book. – From dust jacket b-393