Most school-age children are at times away from adult supervision. Perhaps it's when walking to and from school, playing in the park, at home while parents run to the store or mail a letter or while parents work.
Parents have the responsibility to help a child prepare to be alone.
This means helping them to know and follow safety procedures, understand what to do in emergency situations, feel confident and secure and learn to spend their time wisely. There is no single answer or magical age when a child is ready to be left alone. The situation that your child is in may make a difference. Location, absence or presence of neighbors, and the length of time you are away all have some bearing on your decision. You need to feel that your child is mature enough to handle the responsibilities of being on his or her own.