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.

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 ...

For Mr. Santos, math can also inspire ideas about structures that have already been built — a new way to see and appreciate ...

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.