Much of Dear Mr. Henshaw focuses on how Leigh Blotts learns to become a problem solver. Minor problems present themselves throughout the course of the narrative, and Leigh learns how to manage the situation, cope with the difficulties, or solve the problem completely. An example of this is Leigh's writing. He would like to become a much better writer, like Mr. Henshaw, so upon his favorite author's suggestion, he begins to keep a journal. Because of his hard work and effort, Leigh later wins a writing contest.
Another example of conflict resolution in Dear Mr. Henshaw is Leigh's stolen lunches. His mom always puts in special treats and tidbits from her catering job, and Leigh becomes frustrated when they keep getting stolen. He cleverly solves the problem by creating an alarm for his lunchbox that would sound when somebody opened it.
The main conflict of the novel, however, is a problem that Leigh cannot solve on his own. Leigh really wishes for his family situation to improve. He worries about his mother working so hard to support him and wants his truck-driving father to have more time for him. These conflicts, of course, are issues that Leigh cannot fix by himself, but his efforts at being a better writer and trying to solve the problem with the lunchbox have helped him realize that some problems cannot be solved right away. Leigh learns patience and an appreciation that some things in life just take time.