Which is better: voluntary fasting or helping children memorize the Qur’an?

It is recommended to combine raising children with teaching them the Quran whenever possible. If this is not feasible, then the best approach is to raise the children and teach them the Book of Allah, because the Prophet, peace and blessings be upon him, said: "The best among you is he who learns the Quran and teaches it." This is also because parents are responsible for raising and disciplining their children, and because the benefit that extends to others is better than the benefit confined to oneself.