QUAD-RULED - Set of (12) twelve 9-3/4 x 7-1/2 inch thread-bound, wireless 80 sheet/160 page, quadrille 4 x 4 graph paper composition books with 4 squares per linear inch, perfect for plotting math equations and creating graphs.,DURABLE - Sturdy hardcovers, front and back, in 4 assorted colors; pages are thread-bound for extra strength,ASSORTED COLORS - Each book is identical inside with a front/back cover in red, blue, purple or green,PERSONALIZE - Inside front cover has a class schedule grid and call-outs for name, date, school and more,HELPFUL HINTS - Inside back cover includes USEFUL INFORMATION such as a standard to metric conversion table for linear measurements and volume, and multiplication table