Sudokus are the ever-popular number placement puzzles that give your brain a workout. Spanning a number of difficulty levels, this collection comes in a handy pocket-sized package so you can pop it in a bag for puzzling fun on the go. - EXERCISE YOUR BRAIN: Give your mind a great workout as you pit your wits against these number-placement teasers.- REDUCE STRESS: Feel your stress melt away as you focus on these satisfying puzzles.- POCKET-SIZED: This handy layout is perfect for carrying on your travels or just to keep by your bedside.