Like many mathematicians, Ken Ono cherishes the dense Japanese chalk that brings his work to life on slate blackboards. The professor often hands those white Hagoromo sticks to students so they, too, can wrestle with theorems and proofs in front of the class. It is a tactile ritual, he believes, rooted in the math traditions of the ancient Arabs and Greeks.

Now Ono must make do with a digital pen, an iPad and a Zoom video link as he launches a remote session of Math 3354 for the University of Virginia.

For U-Va. Not at U-Va.

“Great, can everybody hear me?” Ono asked as the 75-minute class began one afternoon last week. He was talking from a bedroom office in Charlottesville, with about 35 students tuned in from across the state and beyond.

“I’ll look in the chat box for a bunch of yeses,” he said. “Welcome back to U-Va. on coronavirus. . . . It’s not perfect, but we do the best we can.”

Across America, colleges and universities are racing to rescue spring terms from the wreckage of the coronavirus pandemic. Faculty members are on the front lines of this massive and unprecedented shift from in-person to online teaching. The tech-savvy are guiding the technophobes in the use of video tools such as Panopto, Webex and Zoom.

Some remote classes were disrupted last week at the University of Southern California as online infiltrators spewed “racist and vile language,” according to USC officials; the incident was part of a trend known as “Zoombombing.”

Inevitably, more disruptions lie ahead. Faculty members know that glitches and crashes will happen. Many students will struggle to get reliable Internet access, decent computers or accommodations needed for disabilities. Still, legions are relying on professors to provide at least a semblance of academic routine. Without that, students are at risk of delay or derailment on the path to graduation.

“The faculty have to be flexible and patient,” said Marcio A. Oliveira, assistant vice president for academic technology and innovation at the University of Maryland. Kindness is essential, policies bendable. Instructors must understand, Oliveira said, “that for students, the same deadlines and the same ways of teaching may not work in this period right now.”

The digital transformation of higher education has been building for years. In 2012 and 2013, universities discovered that massive audiences could be developed for online courses from star professors on a range of topics, from artificial intelligence to modern poetry. Even before the pandemic, many educators had “flipped” their classes, giving students lectures online that they could review on their own time so that class hours were freed for discussion and projects. It is common, of course, for universities to offer entire courses and even degrees online. Those ventures typically require months of planning.

What makes the coronavirus crisis unique is the sudden prohibition of in-person classes, with scant time to adapt.

Even St. John’s College in Annapolis has made the shift. At the 500-student liberal arts school, faculty members are called tutors, and classes are conversations about the great works of Western civilization. Some tutors are so tech-averse that they don’t use email. Yet the college in Maryland’s capital, shuttered for face-to-face teaching, has resumed via video with only a few cuts to the reading list because of lost time. (Out are Aristotle’s “Poetics” for freshmen and Rousseau’s “The Social Contract” for juniors.)

“I’ve been just elated,” said Panayiotis Kanelos, the college’s president. “It’s doable. There are things that are lost and things that are gained.”

For many public universities, the scale of the mid-semester switch is staggering. U-Va. has more than 16,000 undergraduates and U-Md. more than 30,000. Both flagships also have thousands of graduate students whose coursework and research have been disrupted under the orders to stay home.

The universities have taken steps to secure computer and WiFi access for students who lack those tools. Officials say they are working to help those with disabilities and special needs. Both schools also are making undergraduate courses pass-fail unless students choose to receive a letter grade.

There is no single formula for remote teaching at schools with thousands of seminars, laboratories, lectures, performances and courses in other formats. In general, educators say, many lab classes will rely on data collected from experiments underway or finished before the coronavirus shutdown. They’ll move to data analysis. Likewise, professors and students in performing arts and other fields oriented to physical gatherings and activities must shift gears.

At College Park, classes resumed Monday after an extended spring break to give faculty time to prepare.

For Tammatha O’Brien, a senior lecturer in entomology, the transition is not daunting. She has used video lectures for years to maximize the value of face time with students. The lectures are, in essence, narrated slide decks. “They can pace it, slow it down, go faster, go slower,” she said. “Students actually really do enjoy it.”

O’Brien is teaching ecology, endocrinology and anatomy/physiology. She plans to use online discussion boards and video lectures to finish the term. Most instruction will be “asynchronous” — meaning students will not be required to meet online simultaneously. That is meant to help those who live in different time zones or have obligations or distractions at home.

Grades will be based on quizzes and projects completed during the semester, but O’Brien doesn’t plan to give students final exams. “It’s going to take a lot of stress off them,” she said.

Barnet Pavão-Zuckerman, an associate professor of anthropology at U-Md., has a steeper learning curve. She teaches ecological and evolutionary anthropology to 130 students. A self-described extrovert who loves to lecture, she knows how to scan the room for facial cues to check whether students are lost or engaged. She had never recorded a lecture until one she gave a couple of weeks ago on the extinction of dinosaurs.

Now Pavão-Zuckerman is churning out bite-size lectures from her basement in Colesville, Md., for students to review at their convenience. As props, she uses skull replicas grabbed from a campus lab. Her 10-year-old daughter makes cameos.

“Hi, everybody,” the professor said in one 10-minute video. “This is my first lecture from home using Panopto. I’m in my basement that shows the books behind me instead of the kids’ toys on the other side of the room. So — we’re going to talk about the emergence of primates today. And this is very strange because I can’t see your faces.”

Pavão-Zuckerman said she plans to use Zoom for office hours. Her student teaching assistants have scoured the Internet for interactive tools to simulate labs. The class will have open-book quizzes and tests. She cautions that there are limits to what can be done in a quick online retrofit. “To do this for real, we would like six months to prepare,” she said.

At U-Va., remote classes began March 19. The university surveyed faculty beforehand and found that about two-thirds felt comfortable teaching their courses virtually. But many needed guidance.

“I’m a technophobe,” said Herbert “Tico” Braun, a veteran professor of history. “This stuff scares the hell out of me. I get in front of one of these machines, and I start to perspire. . . . I really didn’t know how I was going to be able to do this.”

Braun’s first attempt to hold a 75-minute Zoom seminar “did not go so well,” he said. He found himself talking too much and too fast. The second time, he slowed down. He gave students more chances to speak up in a discussion about Canadian philosopher Charles Taylor.

“Basically, it’s a matter of being more confident with the screen in front of you,” Braun said, “breathing more slowly and being able to do this. And it happens. And it works.”

In the last 10 minutes, Braun opened up the class for students to talk about where they are and how they’re doing. “This is traumatic for them,” he said, “in ways that are almost unimaginable for us.”

Evan Brandt, 21, a junior majoring in math and Spanish, said it is surreal to take classes from his basement in Gainesville, Va. He misses swimming the butterfly for U-Va.’s club team and hanging out on spring afternoons on the famed Lawn. “It’s a big bummer,” Brandt said.

But he said he is astounded at how fast professors have reshaped their courses. “I still feel like I’m getting U-Va. kind of quality,” he said. His classes meet at the same time they did when Brandt was in Charlottesville. “Which I actually like because it keeps me on a schedule,” he said.

One of those classes was Ken Ono’s survey of modern algebra. The professor said many in his field are skeptical of online teaching. “You would think mathematicians would be into computers, into technology and all that,” he said. “Honestly that’s not true. We are very traditional.” But events have forced them, for now, to store their chalk.

Ono said he is impressed that the university can carry on. “If this had happened 10 years ago, we would be in major trouble,” he said. “The semester would have to be canceled.”

On Wednesday, Ono discoursed on group theory and theorems of Lagrange and Fermat as students watched him sketch, with a sure and rapid hand, the symbols of high-level math. Some asked questions in the chat box or offered answers to the professor’s call-out queries. They wondered how they would submit homework. (By emailing images of it, the professor said.)

They were also keen to guide Ono as he drew a smiling octopus to wrap up the lecture — because why not? “Web its tentacles,” wrote one. “Give it ears,” wrote another. “Spots,” wrote a third.

“All right you guys, I did my best,” Ono said, lamenting that the digital pen was suboptimal for adding spots. “So I’m going to call this ‘Happy Octopus.’ See you Monday.”