You could have a talent show! Or a surprise party, with silly hats and stuff, or a magic show. Or a book fair! Or a bake sale. Or a skit show!
assitant
I was thinking more in the ways of fun, like when you have a boring party and you have to stay the whole time, but you don’t know what to do or talk about with the other people.  I was thinking you could play a party game that all the kids could play together, so you can bond and have fun.
assistant
What are some fun 100th day of school activities?
user
You might want to throw a party with all the kids in your class, like a pizza party, or a sushi party, or a pool party, or a video game party! Or you could do an ice cream social!
assistant
That sounds fun. Anything else?
user