September 16, 2025, is the only date that fits the definition this century. Here’s the specific math to add it all up: 3 multiplied by itself is 9, 4 squared is 16, and 5 squared is 2025. On top of ...

Once a century, a very special day comes along. That day is today — 9/16/25. Pi Day (3/14) often comes with sweet treats; Square Root Day (4/4/16 or 5/5/25, for example) has a certain numerical rhyme.

There’s a delightful mathematical moment in the movie Merry Andrew, when Danny Kaye, playing schoolmaster Andrew Larabee, breaks into song to teach the Pythagorean theorem. I was reminded of this ...

If you have taken high school geometry, you have learned about the Pythagorean Theorem (even if you don’t remember it today). The theorem is an essential part of Euclidean geometry, and it goes as ...