How long should my child be able to play by himself?

Every child is different and the length of time kids can amuse themselves depends a lot on their interest in a particular toy or activity.  Usually, the younger the child, the shorter the time he or she will play independently. For a three-year-old, 5 – 10 minutes may be a long time. For a 5 year old, 15 – 30 minutes might not be unreasonable, if the activity is motivating.