Mums and dads of teenagers: Does your kid seem extra enthusiastic about addition and multiplication these days? I’m sorry to break it to you, but the calculator app he’s been grinning at all evening may not be the trusty maths device that it seems. It could be a digital safe, hiding photos he doesn’t want you to see. Here are some ways to find out.

When it comes to teens getting enough sleep, numerous forces are working against them. Early school start times are wreaking havoc on their circadian rhythms. An overload of after-school activities is turning bedtime into gotta-start-on-homework time. The buzz of texts from friends, the screens shining in their faces and the constant lure of just one more game or episode of Riverdale are keeping their brains wired well into the night. And all the lectures coming from concerned mums and dads seem to be dissolving into thin air because, well, adolescence. And so they slog through their days, cranky and short-fused and barely able to respond to basic questions. As parents, you wonder if there's anything you can do to help.

High school and university students are suffering from unprecedented levels of anxiety, and anyone raising teenagers these days knows they're coping with huge amounts of stress. This goes double for girls, who have what Rachel Simmons calls "role overload" in her book Enough as She Is: How to Help Girls Move Beyond Impossible Standards of Success to Live Healthy, Happy and Fulfilling Lives. Girls have to be smart and beautiful and athletic and ... they have to look as though playing all these roles takes no effort at all.

I get it -- textbooks are weighty tomes that feel like they're more useful as a defensive weapon than an engaging read. But it's still important to actually read them instead of treating them as a "find the potential-test-answer" word search.

There's a reason teens are nodding off in class, and it's not just that last lecture on polynomials. They're sleepy. And a reason why they're sleepy is that school starts too damn early.