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.

What do patterns, puzzles, and art have in common? Expand your horizons and see the connections. You’re using math and don’t even know it. Unlock the beauty of mathematics at WonderLab’s Pythagorean ...

Pythagorean Triple Square Day, as one man affectionately calls 9/16/25, is a day like no other this century. On 9/16/25, celebrate a date of mathematical beauty Once a century, a very special day ...