In a life hack we never saw coming, Facebook user Kelly Rose Sarno demonstrates quite possibly the easiest way to cut a watermelon. Using just a long piece of dental floss, she pulls the string tightly under the already-halved fruit and makes a clean cut. Then, she raises the piece of floss and "cuts" the rest in triangles, no knife required. Watch for yourself: There's a reason this hack has been going viral since it was posted in 2018: It can be super helpful for teaching children how to cut without actually using a knife, which in turn is great for if you're picnicking and want to travel light or just those times you don't feel like washing the dishes. Here's hoping Sarno will come up with an easy hack to core pineapples next.Check out 10 fruit and veggie-slicing devices you never knew you needed in the related video above.