It's 3 p.m. Do you know where your children are?

With the influx of cellphones and other technology into kids' lives, parents increasingly do — even in the classroom.

A 2015 study by MediaSmarts, a Canadian not-for-profit focused on digital literacy, says over a quarter of students in Grade 4 own cellphones, and that skyrockets to 85 per cent by Grade 11. Some children as young as eight own phones.

And many will take their phones to class.

Millions of Canadian kids are heading back to school — some earlier than others — raising the questions of what age is too young to have a phone and how owning one helps or harms kids.

According to one study, 85 per cent of Grade 11 students in Canada own cellphones. (Michael Loccisano/Getty Images)

'Kids should just be kids'

The parent of one eight-year-old thinks that's too young.

"I am totally against it," says Melissa Joyce on her daughter Aniah having a cellphone, although the competitive dancer and avid soccer player keeps asking for one. "Kids should just be kids."

A cellphone for Aniah would open a "whole other realm that she doesn't need to be exposed to," says Joyce. She notes access to technology and the internet, notably social media, is especially problematic for young girls.

Thierry Plante, a media education specialist at MediaSmarts, says the omnipresence of cellphones could keep kids plugged in to social media, which can be problematic.

According to a 2012 MediaSmarts study, over half of Grade 11 students in Canada sleep with their phones because they fear missing messages. (Jean-Sebastian Evrard/AFP/Getty Images)

"Social media can exacerbate problems" like bullying, harassment and FOMO (fear of missing out), he says, noting school should be one of place kids can have "digital breaks."

Plante gives the example of a 2012 MediaSmarts study that found over half of Grade 11 students sleep with their phones because fear of missing messages.

"Bringing cellphones to school could bring with it other problems you might have," he says.

Some schools have considered banning cellphones. The Toronto District School Board, Canada's largest, did just that from 2007 to 2011.

"We all know that technology is here to stay, and so the school board has to get with the times," Ryan Bird, a spokesperson for the TDSB, told CBC News in 2015.

Some schools have considered banning cellphones, which the Toronto District School Board, Canada's largest, did from 2007 to 2011. (Getty Images)

Health and academic consequences

However, many schools and classes have increasingly been using technology to teach. The results vary.

"There has been a lot of research on whether or not devices in school are useful," says Plante. "We are still in the discovery stage."

Plante says one literature teacher used Twitter to teach Shakespeare, having the students create Twitter accounts for characters and live-tweeting during class.

However, not everyone has been able to integrate technology in the curriculum.

"There is a bit of a struggle to use devices in a way to support learning," says Plante, noting the success of BYOD (bring your own devices) policies largely depends on the teacher. "Some teachers find them disruptive."

Many schools use technology to teach. Thierry Plante, a media education specialist at MediaSmarts, says success depends on the teacher. (Jung Yeon-je/AFP/Getty Images)

Some researchers suggest there's a link between cellphone bans at school and increased academic performance.

In a May 2015 research paper by the London School of Economics, researchers sifted through surveys from 91 schools in England with cellphone ban policies and compared their standardized test scores for 16-year-olds to the rest of the country's.

It found overall student scores improved by 6.41 per cent.

Although she does not support a ban on cellphones at school, Joyce believes they're not necessary in that environment.

"If [kids] need to use the internet, schools have computer labs. If they want to play games, they have recess," she says. "If there is an emergency, she can call me from the office or a counsellor can call me."

"Kids should be using pen and paper."

A pupil uses his phone for research during class in Winterbourne, England, in 2015. Researchers for the London School of Economics suggest banning cellphones at school can improve academic performance. (Matt Cardy/Getty Images)

Some studies suggest excessive time spent using screens, including cellphones, can affect children and youth adversely, stunting emotional and cognitive growth, warping a young person's perspective on social norms and causing health problems such as poor eating and sleeping habits.

In 2012, the Canadian Pediatric Society came out with these guidelines for children and adolescents:

Children under 2: no screen time is recommended.

Children 2-4: less than one hour a day.

Children 5-11 and youth 12-17: no more than two hours a day; lower levels are associated with health benefits.

Too much screen time harms "aspects of cognitive and psychosocial development," writes the CPS.​​

The Canadian Pediatric Society recommends children under two should not spend any time in front of screens because doing so 'negatively impacts aspects of cognitive and psychosocial development.' (CBC) Plante agrees. "The time spent in front of a screen is time taken away from interacting with the real world and with real people and the benefits of cognitive development," he says.

For JP Casino, parent of two and owner of KidGadget, an online tech and gadget store for Canadian parents, cellphone usage for children is "less age-dependent and more need-dependent." Casino says he knows teenagers who don't have or want a mobile phone and 12-year-olds who do.

Casino says some of the need comes from a desire for safety.

"Some children walk some distance to get to school, and parents can't always accompany them," he says.

A cellphone can help a parent track kids on their way to and from school. Kids get "a means to get a hold of [parents] in case of an emergency."

Joyce says the only situation where she could imagine giving Aniah a cellphone is if she started walking home by herself in Grade 7 or 8.

For parents who balk at the idea of handing their kids a smartphone, Casino recommends other devices that have speech and tracking features.

"There are an emerging number of kids' wearables, like smartwatches, that have GPS and calling features," he says. Such devices use less data than phones.

JP Casino, with his six-year-old son Joshua, says parents need to 'be vigilant and educate themselves.' That includes knowing what apps their kids use, and even their passcodes. (CBC)

Casino's six-year-old son Joshua uses Tinitell, a watch with mobile phone and locating features.

"He's a bit young for a cellphone," he says. The watch does not have the capacity to run Snapchat and other social media platforms that may put kids at risk.

Although Casino does not believe cellphones are an absolute necessity for school-aged children, he thinks it is important for them to be more tech-literate because much of society, including classrooms, is becoming more plugged in.

"More teachers are talking about and using apps, and devices are starting to take the place of (the) notebook," he says. "There's also peer pressure" to own a phone.

But Casino says parents need to "be vigilant and educate themselves." That includes knowing what apps their kids use, and even their passcodes.

"A cellphone is like anything else, it's a tool," says Casino.

"Until kids can demonstrate responsibility, parents should not let them use it completely unsupervised."