Consider this sequence of numbers: 5, 7, 9. Can you spot the pattern? Here’s another with the same pattern: 15, 19, 23. One more: 232, 235, 238. “Three equally spaced things,” says Raghu Meka, a ...

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 ...

Barbie caught a lot of flack back in the ’90s for declaring, “Math class is tough!” Today we find ourselves in the disorienting position of defending her. We recently got a note from an anonymous ...

A key part—though surely not the only part—of early-grades math is ensuring students get the basic arithmetic functions down and, beyond that, making sure they’re able to swiftly and automatically ...

Hear that change jingling in my pocket? Good. I have two little questions for you. I have a quarter, a dime and a nickel. How much money DO I have? I have three coins. How much money COULD I have? The ...

The Sudoku puzzle in the Sunday comics section says, “There is no math involved. You solve the puzzle with reasoning and logic.” However, reasoning and logic are at the heart of mathematics. It would ...