From left, Jack Doyle, 13, Ryan Ward, 14, Aiden Franz, 13, and Gray Rager, 14, use their cell phones during lunch at Westland Middle School in Bethesda, Md., on Nov. 2. (Michael Robinson Chavez/The Washington Post)

It’s been a long time since mobile phones arrived in the nation’s schools, but educators are still grappling with what to do about them.

Should they be allowed in elementary schools? What about middle-schoolers using them at lunch? Which limits make the most sense for devices so ubiquitous?

What has become a more settled matter for high school students is sparking questions and controversy in lower grades, some two decades after mobile phones became an inescapable part of the cultural landscape.

The debate has emerged in Maryland’s biggest school system — in suburban Montgomery County — where some of the rules have been relaxed in recent months.

It used to be that students through fifth grade could carry cellphones only with special permission. But over the years, an increasing number of parents wanted their elementary-age children to take phones to school, often believing kids would be ­safer — walking home or in an emergency — with the device at the ready.

Westland Middle School in Bethesda, Md., allows students to use cellphones one day per week and only at lunch. (Michael Robinson Chavez/The Washington Post)

As the Maryland district recently moved to do away with the old rule, other parents objected — shocked that children as young as 6 or 7 would be permitted to bring smartphones to school. One father recalled his child’s school banning fidget spinners and Pokémon cards. Why allow cellphones?

“A phone would be more of a distraction,” said Art Bennett, who has three children in Montgomery schools. “Unless there’s a demonstrated need, I don’t see why there ought to be phones in elementary school at all.”

The change in district rules, which took effect this fall, also allows middle school students to use cellphones during lunch if principals give the okay — an idea that has conjured images of children bent over phones in the cafeteria and left parents, already worried about the hours their children spend on screens, dismayed.

“We all know the phone is a blessing and a curse,” said Lisa Cline, co-chair of a safe technology subcommittee of the countywide council of PTAs. “I don’t see why we want to make these children into little adults.”

While there is little national data on how school systems handle such issues, it appears that approaches vary widely. Some schools ban smartphones, while others allow them in hallways or during lunch periods, or actively incorporate them into instruction .

“I really don’t see a consensus,” said Elizabeth Englander, a professor at Bridgewater State University in Massachusetts. “Nobody really knows what to do. I think everybody’s trying out different things and seeing how they work.”

Englander said that a survey of third-graders in five states found that 40 percent had a cellphone in 2017, twice as many as in 2013. Among the third-graders who had a phone, more than 80 percent said they brought them to school daily, according to a preliminary analysis.

In the D.C. region, rules often vary by school.

In Fairfax County, some middle schools allow cellphones during lunch, and some don’t. In Prince George’s, they are allowed with principal approval. In the District, public schools also develop cellphone policies at the school level. At least one middle school — Hart — gives phones back to students at lunch.

In Montgomery, school system officials say they are changing with the times, in an increasingly digital world where more parents buy their children phones and more children tuck them into backpacks, pockets and lockers. Students in all grades are responsible for using them appropriately.

“Five or 10 years ago, many elementary school students didn’t have cellphones,” said Pete Cevenini, chief technology officer for the school system. “Now, many of them do.”

But some parents voice concern that the end of a requirement to get a waiver will mean more devices in elementary school. Children are not allowed to use phones during school hours, unless a teacher blends them into instruction. They may use them after dismissal and on school buses under the new rules.

A recent report by Common Sense Media, a nonprofit group that helps families navigate issues related to media and technology, showed mobile screen time on the rise for children 8 and younger.

Nationally, as more phones have gone to school in the past decade, educators have turned their focus from the mere fact of having a device to any inappropriate behavior, said Ann Flynn, of the National School Boards Association.

As Montgomery’s middle schools consider the issue, many parents worry about the broader phenomenon of screen time. They say students need face-to-face contact to develop social skills, expand friendships and learn to navigate uncomfortable situations; they don’t need another place where phones take over their attention.

Angie Melton, a mother of four from Kensington, said two of her children reported near-silence at lunch when their middle school allowed phones for a week.

“They get in their virtual worlds, and I want them in the real world,” she said.

Others question whether cellphones at lunch may add to the gap between the haves and have-nots. “Does that mean some kids get locked out of what’s happening socially at lunch?” wondered Cathy Stocker, a mother of two and a PTA volunteer in Bethesda.

Justus Swan, a sixth-grader at Takoma Park Middle School, said he is in no hurry to bring cellphones into the day’s largest stretch of free time. Lunch is about socializing, he said, and with phones in hand, students would be less tuned in to conversation.

“It defeats the point,” the 11-year-old said.

But the phone-friendly lunch has supporters.

Matthew Post, the school board’s student member, said that he backs a school-by-school approach but that phone privileges at lunch would give students the chance to learn about responsible use and get ready for the world beyond middle school. As he has visited schools, he said, he has found the lunches where phones are allowed no less social. “There was the same chatter and bustle that I saw in every middle school lunch,” he said.

At Westland Middle School in Bethesda, 14-year-old Gray Rager worked with another student government leader last year to make the case for phones during lunch. Kids can text parents, check grades online, play music, watch videos, he said.

“It’s a nice freedom to have,” he said.

Westland Principal Alison Serino said a survey showed that students overwhelmingly favored the idea — but that parents overwhelmingly did not. As a middle ground, Serino has allowed cellphones at Friday lunches this year, under ground rules: No Snapchat or Instagram. No violent games or taking photos or videos. Ear buds for playing music.

It means another 30 minutes of screen time in a week, Serino acknowledged, but she has found that students are still social at lunch. “I’m seeing the vast majority of kids are still interacting with each other,” she said.

At Loiederman Middle School in Silver Spring, Principal Nicole Sosik allows cellphones at lunch five days a week but says she’s made clear the privilege will end if students are not responsible. Those who lack phones may use the school’s Chromebook laptops at lunch.

It’s a change from the past, she said, when “a lot of time was spent monitoring electronic devices and confiscating them.”

In recent years, students in some Montgomery classrooms also have used phones as part of learning, under “bring your own device” initiatives.

Students are supposed to use the district’s network while in school, and social media sites in Montgomery are blocked for ­middle-schoolers, although some break the rules and go off the network to access them. High school students can use Facebook and Twitter through the network.

Students see technology as their social glue, and research has shown that cellphone use does not reduce the quantity of face-to-face time, said Scott W. Campbell, a University of Michigan professor of communication studies. Kids tend to view socializing in person and through devices as “one ­hybrid space,” not competing realms, he said.

Researchers are exploring possible negative effects related to concentration, academic focus and overstimulation, said Douglas Gentile, an Iowa State University psychology professor. On the positive side, he said, educators are using devices in classrooms as a way to engage students in course material.

Larry Rosen, a professor emeritus who studies the psychology of technology at California State University at Dominguez Hills, says research has shown that heavy users of cellphones feel anxious when they can’t check their phones — and that anxiety interferes with learning.

“Their eyes may be on the teacher, but their minds are elsewhere,” Rosen said.

Others noted that a 2015 study of high schools in four cities in England found that performance on high-stakes exams improved after a cellphone ban was imposed, with the greatest gains for disadvantaged and underachieving students. "What we can take from this is the unstructured presence of phones in schools is bad," said Richard Murphy, assistant professor of economics at the University of Texas at Austin, who noted that the study did not examine mobile phones as a teaching tool.

Kendall Johnson, 13, is pushing the issue at Montgomery County’s Farquhar Middle School in Olney, where she said it came up a lot as she campaigned for student government president. “It’s just another source of entertainment for when you’re at lunch, or you can use it if you want to check on the local news or text your mom,” the eighth-grader said. Even a day a week would be a start, she said, although she would “like to see it grow into something more.”