Our local public schools, in an affluent Boston suburb, are so good that they don't need to consider subject acceleration in elementary and middle school /sarc. So the role of public school math classes for our children is mostly credentialing rather than learning
Whew, I almost missed the sarcasm and I was getting ready to move to Boston for those "good" schools
Lepa,
I have a similarly advanced child. He was moved to 1st grade math in the most well performing local PS in his K year. Yet there was nothing new there for him. He too did not have any "formal" math because he went to a Developmental Play based preschool and daycare. Our family has a math background and we talk a lot about math concepts on car rides and during bath time, that is all. DS was so bored in school that I started afterschooling higher level math formally using a curriculum at age 5 so that he could understand that there was more to math than what he already knew. I used Miquon and Singapore Math and we have gone on from there.
If your child is very capable in math and is not enriched, he is probably going to understand new concepts in the first few minutes of being taught them in the classroom. And spend the rest of the days/weeks being bored until something else new is taught (check your school's math scope and sequence - the K and 1st grade curricula usually cover simple concepts). So, I would suggest that you keep enriching him.
From what you posted, I believe that he would love to read books by Theoni Pappas - especially The math adventures of Penrose the Mathematical cat -
http://www.amazon.com/The-Adventures-Penrose-Mathematical-Cat/dp/1884550142Good luck.
