100th Day of School

Aaliyah, my kindergartner, came home today and announced that her class will be celebrating it's 100th day of school tomorrow. I already knew about it from the monthly calendar that her teacher so diligently sends every month. The bulletin boards outside of every Kindergarten class also have art displays with the 100th day of school theme. Its a big thing at her school. I asked her with a blank face, what it meant. Why was it so special. She immediately replied that it