What age to Begin Formal Children's Classes ?

"As to the Children: From the age of five their formal education must begin. That is, during the daytime they should be looked after in a place where there are teachers, and should learn good conduct."
Abdu'l Baha, in Baha'i Education: A Compilation, p. 39


"And when the child hath reached the age where he can make distinctions, let him be placed in a Baha'i School, in which at the beginning the Holy Texts are recited and religious concepts are taught. At this school the child is to study reading and writing as well as some fundamentals of the various branches of knowledge, such as can be learned by children."
Abdu'l Baha, in Baha'i Education: A Compliation, p. 40