This article by the Bluedorns is worth a read, it's too long to c&p here, so I'll post a link for anyone interested:

http://www.triviumpursuit.com/articles/research_on_teaching_math.php

The Bluedorns advaocate classical education, but not until age ten.  They believe that the focus should be lifeskills and character training for young children and that most kids aren't ready for formal schoolwork before age ten, especially boys. 

This part of their article that I have highlighted struck a cord with me:

What we suggest is:

1. Formal textbook or workbook instruction in arithmetic may begin at age ten. It is about age ten that the developmental light bulb goes on, and the child becomes capable of a great deal more mental and physical skill. (Of course that’s not an absolute rule. With a few children, it is as early as eight. We call them "bright" children because the developmental light bulb goes on early.) Waiting until the child is developmentally prepared to handle the concepts makes instruction in arithmetic very easy, because the child learns very quickly.
2. There is no necessity for formal teaching in arithmetic before age ten. Once all of the developmental parts are there, most children can learn – in a few weeks – everything which they might have spent six years learning (kindergarten through fifth grade), that is, if they haven’t already learned it through questions and experiences and working things out on their own — which is generally the case.
3. Depending upon the child, upon the method, and upon the subject matter covered, there exists the potential for developmental harm from the formal teaching of arithmetic before age ten. Small children cannot understand many arithmetic concepts at an early age. We can teach them to perform the process, but we cannot make them understand the concepts. The child "learns" to hate "learning." The child’s understanding develops along the wrong lines. He may actually develop mental "blocks" to arithmetic – actual physiological blocks in the brain. (This may give new meaning for the term "blockhead.")
4. Not formally teaching arithmetic before age ten frees up a lot of time for other activities which will build the vocabulary of the child. Vocabulary is the number one index of intelligence. Developing vocabulary was one of the deliberate foci of ancient education. We waste valuable time for developing vocabulary and verbal language skills if we instead spend those hours teaching a five year old to count by fives. (He’ll know it intuitively by age ten anyway, without ever being taught.) Instead, we ought to spend those hours reading to him. We only have so much time in the day. Do we want to spend it trying to force math skills into a child who developmentally is not optimally prepared, or spend it doing what is developmentally natural to a young child – learning new words and associating them with new ideas and experiences. Stretch the child’s vocabulary during the formative years, and when he’s developmentally ready to do some deeper thinking, he’ll have a mind prepared to take on the task, and he’ll take off like a rocket.

Please note: We are not saying that no child should ever utter the name of a number before age ten. Not at all. About age four, most children discover money, and there is no hiding numbers from them after that. They encounter numbers all of the time. If we encourage learning, then they’ll be asking lots of questions, and we’ll be full of opportunities to teach numbers and measurement. But we would not encourage using a formal workbook before age ten, unless the child has a genuine desire to do so, he shows that he is competent to handle the work, and it does not take away time from other valuable activities. We are not going to ruin the child if we wait until age ten before beginning formal teaching of arithmetic.