NEW YORK >> In the days before remote instruction began, Chauntae Brown, a second-grade teacher at Public School 80 in Jamaica, Queens, scrambled to teach parents without Wi-Fi how to use cellphone hot spots. She rummaged in her garage to find materials — a world map, a “Welcome” sign, an apple-shaped chalkboard — to transform her living room wall into a classroom. She grabbed a plastic tiara because, she said, “I’m the queen of this castle.”

At 8:45 a.m. on Monday, as her students logged on for their first day of remote learning, one after another, she was thrilled to see them blurt hello for the first time in a week. But all did not go smoothly. A third of the students were not present. There were technical issues. And the class had the feel of a slumber party, since so many children were in their pajamas or in their beds, with parents in the same live shot.

By the second day, though, attendance was up to 88%, and most students were dressed for school. There were fewer technical problems, fewer parents to be seen. Students were so excited about Brown reading “Mercy Watson to the Rescue” aloud that several had already clicked through future assignments.

“I said, ‘Friends, you’re eager, but you have to do the day that it says, because Ms. Brown might change her mind,’” she said.

Anything could change, on any given day, as the largest public school system in the country adapts on the fly to a public health emergency without precedent.

Last week was the first week that New York City’s 1.1 million students were back in session, after schools were closed for a week to transition to remote learning. And given that school will be conducted via computer screens for weeks, if not through the end of the academic year, the city’s 75,000 teachers are faced with a challenge unlike anything else in their careers: Holding the attention of students from ages 3 to 18, educating them in accordance with guidelines, and providing them a patina of normalcy despite not having any of the control of a classroom setting.

Looming over the entire enterprise is a cloud of fear and urgency. It is critical that remote learning succeeds. The alternative is that over 1 million children, in crucial developmental stages of their education, will be permanently set back, with no opportunity to salvage lost time.

In addition, the vast majority of New York City public school students are poor and an estimated 114,000 students are homeless. Around 75% of New York City public school children qualify for free or reduced-price school lunch. For many students, school was often the only place to get three hot meals a day and medical care, and even wash dirty laundry.

It has been jarring, surreal and draining, more than a dozen educators said in interviews, to adapt to a completely new way of working, with everyone forced to interact on screens, for at least part of the school day, as the statistics from the world outside get grimmer and grimmer.

Richard A. Carranza, the schools chancellor, cautioned last week that “not everything is going to go as we plan.” Attendance figures were unclear, since schools were still collecting data from self-reporting.

A “technology gap” persisted in a system filled largely with low-income students, he noted, with 175,000 laptops, iPads and Chromebooks distributed before remote learning commenced to the estimated 300,000 students who lacked devices. An estimated 25,000 to 50,000 wireless-enabled devices are expected to be handed out in the coming weeks, according to the Department of Education.

And while Carranza urged “flexibility and patience,” he also saluted teachers, administrators, parents and students for “rising to the occasion.”

“We are literally flying the plane as we’re building the plane,” he said.

The success of remote learning will look very different for different grade levels, and there are several factors — from the academic subject, to the temperament of the student, to the strength of the internet connection and the user interface of the technology — that can affect the outcome.

Gloria Nicodemi is part of a co-teaching team and teaches earth science to ninth- and 10th-graders, most of them Chinese Americans qualifying for reduced or free lunch, at East-West School of International Studies in Flushing, Queens.

“It’s only day two but it feels like week five,” she said Tuesday. “This is my 16th year teaching, and I feel like I’m a first-year teacher. The amount of work and new things that I’m encountering on a daily basis is astounding.”

Nicodemi and her teaching partner opted not to do live video teaching, but rather to post assignments in Google Classroom at 7 a.m., and then ask students to turn in their work by 5 p.m.

They have made themselves available, with specific office hours, to respond to live questions. They have also set up smaller Google meetings for groups of five students for more personalized attention. But it has been frustrating that they can’t, say, pull a student out of class for a few minutes and go over something in the hallway.

“We had kids asking, ‘How do I draw on this document?’ and I was like, that’s a really good question,” she said. “I know what I would do, but I don’t think they have the same tools on their computers.”

Lauri Posner, a longtime fifth-grade teacher at Public School 87 on Manhattan’s Upper West Side, also reported that the first few days were utterly exhausting.

“It was nonstop from 7:30 a.m. to 10:30 p.m.,” she said. “There’s no way a human being can sustain this.”

She had never heard of Zoom until two weeks ago. But at least she had some familiarity with Google Classroom, unlike many colleagues who only used their computers for email.

After working all weekend, she did a trial run with students Sunday, cognizant that many households had only one device, shared by parents or siblings.

When Posner tried to record herself reading a chapter of the book “Under the Egg” on Monday afternoon, the drumbeat of rain on her air-conditioner drowned out her voice.

Improvisation has been key. On Monday, her students participated in a live class offered by the New-York Historical Society, as a substitute for a visit she had originally planned to the new Dorothea Lange exhibit at the Museum of Modern Art.

Gabrielle Utting, who teaches 11th and 12th grade English to predominantly Latino students at the High School for Environmental Studies in midtown Manhattan, said that she had planned to teach 25-minute classes, half the normal length, via Zoom from her kitchen table in her one-bedroom apartment.

But because her boyfriend, who works in finance, had too much equipment taking up space, she moved to the bedroom.

Was the bed made? Yes. Was there anything on view that was too personal? No. What about that guitar in the background? No, it wasn’t hers.

One student logged in from a very dark room, because she was the only person awake in her household. Another had a pet parrot who would not shut up. Utting’s dog, Desmond, made an unexpected cameo, prompting students to pick up their own dogs for all to see.

“It’s been a little weird and uncomfortable,” she said, “but it feels good to laugh at each other’s pets because it is a stressful time.”

One thing she has been surprised by is how many students have struggled with the technology.

“We often think that younger people are better with technology — and they are better with certain technology, like phones — but they don’t live in homes with desktops, so they’re actually not that tech-savvy,” she said.

Some teachers, sensitive to the emotional trauma the coronavirus has wrought on students, have adjusted the curriculum.

Brian Simmons, an English teacher at Food and Finance High School in midtown Manhattan, which draws mostly disadvantaged students from all five boroughs, said he had planned to teach “Alive,” the account of a 1972 plane crash in the Andes, featuring survivors resorting to cannibalism.

He has pivoted and selected Paulo Coelho’s “The Alchemist,” about a boy searching for a treasure, as an allegory for people facing a major transition.

“This is not a book I would have considered in a hundred years to teach to a 12th grade class,” he said. “But these kids are being robbed of their graduation, their prom. How can we give them some sense of normalcy and inspiration?”

Some teachers have also given new meaning to the concept of remote learning.

Lacey A. Tragesser, who teaches 3-K at River East Elementary in East Harlem, talked to her class of 15 children and their parents or relatives three times, live, Monday.

From the comfort of her tiny apartment, 15 blocks from the school, she read a book, “What To Do With a Box.” It was essential, she said, for her 3-year-olds to see her and their classmates, since they had been out of school for a week.

Then she drove to North Carolina, where her family has a cabin in the Nantahala National Forest. Live instruction resumed Wednesday, with Tragesser seated at a handmade wooden desk outside and reading books aloud in sync with the Reggio Emilia approach.

“I brought the computer outside, and we did a mini-lesson on exploring the outdoors,” she said, in what she called “WFW (work from woods).” “They were so excited to see trees and blue sky and the sun.”

© 2020 The New York Times Company