I wrote the following as part of an upcoming post at Keys of the Universe - Articles on the aligning of Montessori and Common Core, but I thought it was a point to make all on its own:
Non-Montessori curricula are all different, presenting concepts at different times, in different ways; and teachers in regular classrooms routinely do not finish any given text in any given year. Hence, no curriculum or classroom experience can actually meet every standard, especially for every child.
Interestingly enough, Montessori strives to go above and beyond - to ensure that every child exiting the elementary experience at the end of either 3rd or 6th grades, has indeed met every requirement on the local educational standards. Very interesting, given how much flack Montessori takes for simply following the child and not providing "enough."
I understand every school is different, I am thinking here of AMI schools that truly follow the child, which ends up meaning following their albums and providing for the child's interests and learning opportunities at every turn.