"A five year old begins to learn Chumash"

As is known, our Sages established that a five year old should begin to learn Chumash (Avot 5:21). As in all human endeavors, however, we must remember that life is not a science and this is an average age, not a strict requirement.
In general, children cannot control themselves until this age. Rabbi Moshe ben Machir therefore writes in his book "Seder Ha-Yom" not to bring a child to school before this age, since it causes the child much distress with little benefit. One Rabbi in the Gemara told his student, who was a teacher, not to accept a child until the age of six and then feed him like an ox (Ketubot 50 a). Before that, only feed him small portions.
But do not be mistaken: none of this should be done with coercion. One must create a pleasant atmosphere through which the desire to learn is awakened within the child (Rashi ibid.).