Set of 12 quad-ruled, 4 x 4 thread-bound composition books with 4 different-colored covers, 3 each of blue, red, purple and green. Each book contains 80 sheets sewn to the book's spine to provide 160 total pages per book. Quadrille-ruled, with 4 squares per linear inch, these books are perfect for mathematics and plotting quadratic equations. They are a favorite of math teachers and those who want a sturdy mid-sized journal they can easily carry in a purse, backpack or briefcase. The front inside cover has a class schedule grid and call-outs for name, date, school and more. The back inside cover includes USEFUL INFORMATION such as a standard to metric conversion table for linear measurements, volume, and multiplication tables.