They started with morning exercises with Zero the Hero and physical education teacher Jon Greenman. The entire school body counted together to 100 by ones, fives and 10s.
Some classrooms dressed up as if they were 100 years old. Others wore brightly-decorated crowns with 100 items attached - everything from feathers to stickers and fluff balls.
Posters line the hallways each with 100 items - like the Minion with 100 spiky hairs, a shark with 100 teeth, and a Star Wars poster with 100 stickers.