Excellent purchase for fans of Sudoku. Each Sudoku has a unique solution. Mini Sudoku. 230 very hard sudoku on 57 pages. The format 6'' x 9 ''. Sudoku will provide you with relaxation, color your leisure, turn your free time into relaxation, give a vacation from the daily for your mind, add zest, develop memory, develop logical thinking and concentration of attention.All answers are carefully checked and are at the end of the book.Sudoku will support your mental abilities in perfect condition.Sudoku 9x9, separated by smaller squares of 3x3 cells. The entire playing field consists of 81 cells. It is required to fill empty cells with numbers from 1 to 9, each of the digits should appear only once in each row, column, and 3x3 square.An excellent book for free time pastime and mind training.I hope you will enjoy my book. I would also really appreciate it if you could write a review.Thank you.Best regards,Andrii Pitenko