A seemingly simple math problem has gone viral this week, leaving people totally stumped on social media. The equation in questions is: 15 - 15 × 4 ÷ 2 = ? At first glance, it looks like a basic grade ...

Every so often it's good to exercise your brain with a math problem or two that forces you to recall principles you learned decades prior. As elementary as it might feel, you'd be surprised how easy ...