Sudoku Puzzle Book For Adult (HARD) featuring LARGE PRINT. Sudoku is a puzzle in which players insert the numbers one to nine into a grid consisting of nine squares subdivided into a further nine smaller squares in such a way that every number appears once in each horizontal line, vertical line, and square. Trim size 8.5″ x 11″ paper. 9 x 9 grid. 200 pages. 250 pages in total. HARD level 1 puzzle per page. 4 Sudoku answers per page.