Ever shoot your kids a glare or two when they're on their phones at dinner [1] or when you're trying to have a serious discussion? Yeah, us too. But one teacher named Mary Garza took that glare to a more meaningful level by having her students do a little in-class experiment. The premise? Every child had to turn their phone on loud and keep a tally of how many — and what type — of notifications they got [2] during just one class period. And as you can see by the photo, the results are staggering. Mary's project quickly went viral when a man named Joe Becigneul shared it to Facebook, as it makes a sobering point about how phones can affect school performance [3].

"A teacher in the US had her students turn their phones on loud, and every time they received a notification they went up and put a tally mark under the correct category," Joe wrote. "This was one class, one period. Every one of these tally marks is an interruption in a student's education. Cell phones can be toxic to a learning environment."