Sudoku is a brain game that helps train your child's brain by using logical thinking and deductive reasoning skills. By starting them out at a young age, you may find that your children perform better in school, and who wouldn't want that. This puzzle book has all 4x4 puzzles, 100 in total. Instead of numbers, just for a fun variation, letters are used. There are 60 Easy puzzles and 40 Hard puzzles. All are original, you won't find any repeats at...