A graphic artist is testing everyone’s knowledge of the mathematical order of operations with a string of numbers and missing arithmetic symbols. Gergely Dudás, of Budapest, Hungary, shared the new ...

Everyone knows that arithmetic is true: 2 + 2 = 4. But surprisingly, we don’t know why it’s true. By stepping outside the box of our usual way of thinking about numbers, my colleagues and I have ...

Add Yahoo as a preferred source to see more of our stories on Google. Everyone knows that arithmetic is true: 2 + 2 = 4. But surprisingly, we don’t know why it’s true. By stepping outside the box of ...

Everyone knows that arithmetic is true: 2 + 2 = 4. But surprisingly, we don't know why it's true. By stepping outside the box of our usual way of thinking about numbers, my colleagues and I have ...