I have a 5th and 6th grader this year, who wanted to have a 100th Day of School Celebration. There are so many ideas out there--if you are a 1st grade teacher!!! I had to really dig to come up with some age appropriate ideas for my two upper elementary/middle schoolers. We had some friends over just to make it more fun!
At the beginning of the school year, we made a 100 poster and attempted to record one thing a day. This kinda fizzled out, but was a good idea anyway.
We started by seeing who could hold their breath for 100 seconds...well, or who got the closest.
Everyone had to close their eyes and raise their hands when they thought 100 seconds had passed. Daniel was spot on and Tera was one second later.
I found this download here on pinterest:
What can I do in 100 seconds?
How many times can you....clap your hands...say the alphabet....count to ten...hop....stand/sit...blink....write your name. Each student records their estimate before they stop, then the actual count afterwards.