Leading human need with the Moon in Sagittarius is the recognition of his authority and respect of his opinions, as well as a manifestation of optimism and open-mindedness.
Therefore, many of them at some point in their lives, at least for some time, are turning to teaching. The Lunar Sagittarius has an inherent inner nobility. Their fairness and generosity makes them very attractive to the others. Their whole life is painted with some lofty idea, coming from the subconscious, which they may not realize for a long time, but through the prism of this idea they look at themselves and at the world, and evaluate everything that happens.
This position (as long as it is not derived in consciousness) can be called "the pink glasses", which sooner or later they will have to remove, otherwise they never will understand themselves, avoiding chances to meet directly with their internal conflicts.
For kids with the Moon in Sagittarius it is very important to feel that their opinion counts. Their behavior is often authoritative, and even patronizing - in relation to the other children and even toward adults. You should not make fun of it or stop it, as this will cause a significant internal resistance.
Teach your child to listen to himself and to compare his own perceptions with the realities of life. But do not call him to be too much reasonable and specifically set forth all the details, leave him a room for the latitude in his judgments and actions.