The 303 Exercises and Active Games series has been created for parents, teachers, camp counselors, coaches and youth-group leaders who want to help children enjoy being active. Physical activity is vital for tweens' health. Challenge your tween with these exciting and complex activities that are just right for ages 9 through 12. These fitness activities help develop muscle strength, goal setting, friendly competition, determination, strategic thinking, and teamwork. Many of the activities incorporate friends and classmates as teammates or opponents, encouraging group play and leadership. Spiral Bound.