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 ...

Words matter. They indelibly colour our perceptions. Take the overdue revival of debate about the value of memorizing addition, subtraction and multiplication tables in school curriculums. The problem ...

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 ...