Burt Kaliski Jr. (@modulomathy) 3/21/12 2:54 PM #math trivia for #March21: #81 is a square, and the sum of its digits is a square. What other days this year have this property? The one-digit squares all have this property: 1, 4, 9. Among the 15 other day-numbers not already mentioned that are squares, the ones … Continue reading →