keeps your brain logical thinking, even at a young age. Sudoku improves critical thinking and making quick decisions based upon available evidence. is not only fun and interesting. It is a brain game that helps to train the brain of you and your child. also demands attention to detail - noticing patterns and finding the right moment to make a move. This series have four different levels: easy, normal, hard, and expert. This book is easy level. if you need other level, please check "Mike Murphy Sudoku". Sudoku easy level vol.2 Details - Small Print (5x8) to easy take with - 100 Easy Level Sudoku Puzzles Collection (is double than vol.1) You will more and more close to normal level! The goal of Sudoku is to fill in the empty cells, one number in each, so that each column, row, and region contains the numbers 1 to 9 exactly once. Pocket Sudoku: Level Easy 1984096001 Pocket Sudoku: Level normal 1984137085 Pocket Sudoku: Level Hard 1983404314 Pocket Sudoku: Level Expert 1984146394 Pocket X-Sudoku: Level Easy 1985412640 Pocket X-Sudoku: Level Expert 1985317117 Pocket Blank Sudoku Worksheet Book 8*10 1985863634 Pocket Blank Sudoku Worksheet Book 6*9 198586309X Pocket Sudoku Level Expert 30 mini 4*6 1986303470