Fasts during Ramadan hold the promise of great reward from Allah. The Hadith speaks of a number of virtues associated with them. For instance the Prophet has said that previous sins are forgiven of a man who fasts to please Allah.
Another Hadith says that the semell coming out of the mouth of a person on fast is better even than the peruke of the mush. From a third Hadith we learn that Allah says i fasting is specially for Me and I will give the reward for it. Many other similar traditions speak of great virtue of fasting.
Fasting is a command for every Muslim man or women who is a major and whose senses are intact. Any one denying the commanded nature of these fasts in an unbeliever and those missing such fasts during without a valid excuse are sinners and transgressors.
Although minors are not duty bound to fast and pray, we are directed to make them do so even before they attain to the age of puberty in order to acclimatize them to these holy acts. The Hadith says that we should get the child to offer Salat under command even when he is seven. But if he gets tens years of age we may even thrash him if necessary to make him say the prayers. Similarly when a minor becomes strong enough to endure the rigors of fasting let us make him do it as much as he can