Question: What is special about the 81st day of school? Answer: Every day of school is special—480 minutes of precious learning time and filled with fresh opportunities to learn something new. The students in k-eighth grade were surprised when they returned from winter break on the 81st day of school to be greeted with “Happy 81st day of school!” and a fun math challenge. Can you say the number 81 in ordinal form? (Hint: It is related to sequencing.) Is 81 odd or even? What is 81 in Hebrew? In American Sign Language? In Roman numerals? What are the closest prime numbers to 81? How do you write 81 in binary code? 81 is the atomic number of what element of the periodic table? What is 81 in gematria? Who was closest in age to 81 at the time of Yetziat Mitzrayim, Moshe, Aharon or Miriam? What a great way to return to school!