Calcudoku Puzzle Book: 200 Medium to Very Hard (7x7) Puzzles (Adult Brain Games Series)

✓ Great gift for family, friends or work colleaguesThis Calcudoku book is packed with the following features:① 200 Calcudoku (7x7) Puzzles from Medium to Very Hard.② Each puzzle is guaranteed to have only one solution.③ Answers to every puzzle are provided.④ Two puzzles per page (6 x 9 inches) .Playing Calcudoku is not just a fun way to pass the time, due to its logical elements it has been found as a proven method of exercising and stimulating portions of your brain, training it even if you will and just like training any other muscle regularly you can expect to see an improvement in cognitive functions. Some studies go as far as indicating regular puzzles can even help reduce the risk of Alzheimer's and other health problems in later life.Completing Calcudoku regularly helps the brain process both problem solving and improves the logical thought process with the use of deductive reasoning, which can also be applied to approaching real-life challenges in a different manner.Includes free bonus puzzles you can download. Calcudoku Puzzle Book offers hours of entertainment for adults of all ages, from young adults to seniors ♥ We hope this will be an entertaining and uplifting mental workout, enjoy Calcudoku ♥