A spontaneous ending often catches children by surprise, which can result in humor. This type of ending works well if there is little conflict in the story because there is no literary need for a resolution. In place of a resolution or moral as the ending, include a spontaneous event or character. For example, a story about a child working hard to clean up a spill on a couch may result in the mother coming home to congratulate the child for giving her a reason to buy a new couch.
Endings to kids' stories that feature puns and wordplay can result in humor because of a miscommunication or interpretation occurring in the story. These types of endings also introduce young readers to a wider vocabulary and grasp of language. Concluding a story with puns or wordplay works best in stories with light conflict, in which any apparent conflict turns out to be a case of misinterpretation. For example, a story about a child told to make a personal toast at her sister's birthday party may have faced the apparent conflict of struggling in the kitchen looking for ingredients her sister liked on bread, only to find out she needed to make a small speech.
Kids stories with a more significant conflict can end humorously through the use of exaggeration. Exaggeration can provoke laughs in young readers because the outcome is unlikely or unreasonable. If you end your story in exaggeration, build it up by using elements of this writing tool throughout the whole story. For example, set up a story about a bully who frames children in the lunch room, which results in the "culprits" having to do after school clean-up chores. End the story with an exaggerated conclusion, in which the bully is finally punished by having to clean an enormous, never-ending amount of trash. Stories that employ exaggeration as a writing technique work particularly well when illustrated.
Kids' stories with a heavier conflict can also end in irony. Irony provokes humor because it defies expectations by reversing the consequences or letting the reader in on information that the characters do not know. An example of an ironic ending would be a story about a child trying to train his dog for a competition. Along the way, the dog learns nothing and causes a mess of situations. At the competition, however, the dog blows the audience away by doing a trick it was never taught.