How can a son be encouraged to continue memorizing the Qur’an after having memorized five parts, and what are the actions that will help him continue without regression?

Remind the child of the virtue of memorizing the Quran, reward him materially, supplicate for his guidance and success, strive to make him desirous of it, and do not neglect the factor of motivation, as a child may become bored because every worker has a period.