On Wednesday morning, for just a few minutes, the routines unfolding in front of Bancroft Elementary School in Northwest Washington seemed normal. Crossing guard Shaketa Barnes was back at work, excitedly greeting students. “I miss my babies,” she squealed. Principal Jessica Morales cheered on students in Spanish and English as they arrived. Parents hugged their children goodbye for the day.

Sure, there were temperature checks, child-size masks with cartoon characters and staggered arrival times. There were also students bundled in winter jackets and awash with the typical first-day-of-school excitement that they missed in August.

One other difference: Teachers were not present.

The returning students — most of whom are homeless, speak English as a second language or have ­special-education needs — will continue with virtual learning in their classrooms under the supervision of nonteaching staff. Their teachers will teach them from home.

More than 400 elementary students returned to school buildings on 25 campuses, the first time since March 13 that a child in the D.C. Public Schools system has entered a school building for a day of learning.

“I’m ready,” said 8-year-old Jonathan Escobar Cruz, wearing a mask with the FC Barcelona soccer team logo. He was the first student to arrive at Bancroft Elementary to receive his temperature check. “I’m excited to see my friends.”

The 400-plus students are a small portion of the 21,000 elementary pupils that the school system had hoped to return to classrooms this month. And they are an even smaller portion of the 50,000 students the public school system serves.

Still, this was a notable day for the public school system in the nation’s capital. Mayor Muriel E. Bowser (D) has been trying since the summer to reopen school buildings. But her plans have been met with backlash and skepticism from teachers, parents and principals. The city, which has been in contentious negotiations with the teachers union, was unable to find a way to bring teachers back this month.

This wasn’t the plan Bowser wanted, but school buildings did reopen, even as the city’s coronavirus rates are slowly rising and the surrounding region’s school districts have retreated from more-expansive plans for face-to-face instruction.

Students will be in school buildings most days. They’ll be able to socialize with friends at recess. An adult in the classroom can help them log into their ­classes and keep them on track during independent work. And their parents can return to work.

Jonathan’s mother, Nora Celina Cruz, said she doesn’t feel entirely comfortable sending her son back to school during a pandemic, but she speaks little English and so has not been able to help her son with his virtual learning as much as he needs. This is the best option for him, she said.

“He is really frustrated at home,” she said in Spanish.

The 25 school buildings will each open between one and five classrooms, with each room serving between six and 11 students, depending on the grade level.

It was an expensive undertaking to open these buildings. Multiple health-care workers are assigned to each building, taking the temperatures of students and staff members as they enter. Workers are trained to administer rapid coronavirus tests if anyone shows symptoms of coronavirus infection during the school day. An isolation room is equipped with long tables and plastic dividers for those with symptoms.

Every room in use is expected to have upgraded air filters and a portable air-filtration system, which cost $650 each.

Schools Chancellor Lewis D. Ferebee and the teachers have tentatively agreed to a checklist of safety standards that each school building must meet to reopen. The school system said all 25 schools meet these safety standards. Last week, the city announced that it planned to reopen 35 schools. But many could not reopen because of staffing issues, though the buildings met safety standards, according to a school system spokeswoman.

As part of the reopening process, parents, union representatives and school staffers are expected to walk through buildings to verify that safety standards have been met. Parents and union members say that some schools aiming to reopen soon still have outstanding building issues.

The supervised classrooms — which the city has dubbed CARE classrooms — are staffed with existing school support personnel or after-school-program employees. All staffers are volunteering to return, according to the school system.

At Bancroft Elementary, for example, three people — two college students and an artist, all employed by the after-school program — are supervising the three CARE classrooms. The school expects to open more classrooms in the coming weeks, according to Morales. School administrators also will be in the building each day.

Morales said the families of 33 children had accepted slots for in-person teaching before the city abandoned those plans and shifted exclusively to CARE classrooms. The families of 11 of these students later accepted slots in CARE classrooms.

Other students — who speak English as a second language, have special-education needs or come from low-income families — filled the remaining seats. Bancroft opened below capacity Wednesday. Morales said some students still need to get their childhood vaccines before they are permitted to return and expects them to do so in the coming days.

“A lot of our families have been getting eviction notices,” Morales said. “They need to get back to work.”

To open the 25 buildings, the city is closing the campuses’ playgrounds to the community during school hours. Morales said this is a necessary community sacrifice to ensure the safety of the students — who are the most vulnerable for academic loss and whose communities have been hit hardest by the virus.

One Bancroft fifth-grader’s mother goes to work early, so he needed to manage the morning on his own. Morales said the child has been late to outdoor weekend programs Bancroft offers, so the school registrar called him Wednesday morning, reminding him to get up and go to school.

Just before 10 a.m., after the other students had entered their classrooms, the boy sprinted with his book bag falling off his shoulder, down the block toward the school building.

“Run! Run!” Morales yelled in Spanish, cheering him along on his first day of school as he darted past her.