Twenty years ago, this puzzle appeared on a test administered to top-tier math students from 16 countries around the world. Only 10% of test takers got it right. In the U.S., only 4% managed to ...

Solve the math puzzle from our February 2026 issue, where we plan a return passage for a robotic explorer that doesn’t want ...

While many scroll past riddles and puzzles without a second thought, there’s a growing number of online users who pause, squint, and dive headfirst into these brain-twisting challenges. For them, a ...

From Quanta Magazine (find original story here). Most of the important discoveries in mathematics take place after decades or centuries of effort. If you want to attack the biggest problems, you’ll ...

An old calculator uses a seven-segment display, in which numerals are represented by different patterns of vertical and horizontal line segments. But the device is faulty and no longer shows any ...

Imagine someone handing you a scrap of net from a basketball hoop, with knotted red cord attached to the netting, and telling you this bit of string is a clue in a puzzle. How quickly — if ever — ...

You are participating in a holiday gift exchange with a few classmates. You each write down your own name on a slip of paper and fold it up. Then all the students place their names into a single hat.