I can’t remember who taught me this little technique for teaching preschoolers how to manage a puzzle but it is a technique I have used for many years with much success.
When a very young child takes a puzzle and dumps all the pieces out, chances are he or she will have a little trouble figuring out where to put the pieces back.
Before the child moves from simple board puzzles to more complex jigsaw puzzles, it can be helpful to teach the child this simple approach.