But in math class, Donovan was unable, as were most of his classmates, to distinguish a dollar from a quarter, or participate in an exercise in which he was told it would cost $1 to buy a plastic model of French fries and 25 cents for a plastic toy version of a doughnut. An aide working with him and another student could not get a clear response, and after a few minutes, stopped trying.

One morning in mid-March, there was an accomplishment. In a modified yoga class called Getting Ready to Learn, Donovan’s vision teacher slipped off both of his gloves and spent time massaging his stiff arms, which tend to stay bent at right angles. Calmed, he was able to keep them off for the rest of the day.

“If I have one issue with the Department of Education, it’s that one size doesn’t fit all,” said Barbara Levine, the vision teacher, who has worked in city special education schools for 25 years and who wants Donovan to have a music class.

“What I’m seeing is that what they are doing is a great fit for 15 to 20 percent of the kids, and the rest of them, we go well over their heads,” she said.

Ms. Bravo said her goal was to strike a balance between functional and academic instruction, focusing on what is really important: the skills that Donovan will need to help communicate to caregivers in the years ahead. Whether that actually took place, she said, will be looked at.

She is retiring this year, but will recommend that the school scale back its class-switching experiment next year, Donovan’s last. Although the teachers and many of the students seemed to relish the dynamism of the curriculum, it proved too much for a single teacher to learn the individual learning styles of dozens of highly challenged students.

But Ms. Bravo is confident the school is moving in the right direction. “I believe we are a special place,” she said. “Are we perfect? No. But no place is.”