Pinterest is an excellent resource for examples of 100th day of school celebrations. The site provides images as well as celebration activity ideas and collects them all into an easy-to-access form. Simply go into the pinterest.com website and search for variations of the term.
Activities for the 100th day of school have become very popular in early grades. The ability to count to 100 is a key learning objective and students can easily relate to the concept of how many days they have attended school. Projects often consist of bringing 100 of something to school and spending class time counting and celebrating the accomplishment.