The 100th day of school is one of the most exciting days of the year in PreK–2 classrooms. Children have been counting the days since the first day of school, and when they finally reach 100, it is time to celebrate learning, counting and how much everyone has grown.

Unlike most celebrations, the 100th day has no fixed date. Here is how to find yours, how to count to it, and easy 100th day of school activities for PreK–2.

What Is the 100th Day of School?

The 100th day of school is the day your class has been at school for 100 days. Many teachers count every school day from the very first day, so the celebration is a big math moment as well as a party.

For young children, you can say:

  • We count every day we come to school.
  • When we reach 100, we have a special celebration.
  • 100 is ten groups of ten.
  • We have learned so much in 100 days!

When Is the 100th Day of School in 2027?

It depends on your school. Start from your first day and count only the days children are at school, skipping weekends, holidays, breaks and snow days. A school that started in mid-August often reaches day 100 in late January. A school that started after Labor Day usually gets there in mid-to-late February.

Check your school calendar in January, and remember that a snow day moves the date. Many teachers keep the plan flexible and celebrate on the real 100th day.

Count Up to 100 All Year

  • Straws and cups: Every day, add one straw to a “ones” cup. When there are ten, bundle them with a rubber band and move them to the “tens” cup. On day 100, you have ten bundles of ten.
  • A hundred chart: Color one square each morning. Children see the rows of ten fill up.
  • Ten frames on the wall: Fill one dot a day. Ten full ten frames make 100. Practice filling ten frames with our ten frame worksheet maker.
  • Count by tens: Each time you finish a ten, count by tens together: 10, 20, 30...

Easy 100th Day of School Activities

The 100 Collection (Math and Families)

Send a note home a week before: each child brings a bag of 100 small things, such as buttons, stickers or dry pasta. At school, children count their items into ten groups of ten. Keep track of who has brought their bag with our free class checklist.

100th Day Snack Mix (Counting)

Set out ten bowls with ten kinds of snacks. Children count ten pieces from each bowl into a cup: 10 groups of 10 make 100. Always check your school’s food and allergy rules first.

100 Exercises (Movement)

Do ten sets of ten together: 10 jumping jacks, 10 hops, 10 toe touches, 10 claps and so on. Count each set out loud and keep a tally on the board.

When I Am 100 Years Old (Writing)

Children imagine themselves at 100 and draw a picture. Kindergarten and first-grade students finish the sentence “When I am 100 years old, I will...” Preschoolers dictate their idea.

The 100 Cup Tower (STEM)

Give small groups 100 paper cups and challenge them to build the tallest tower they can. Count the cups as you go, then measure and compare the towers.

Estimation Jar (Comparing Numbers)

Fill a clear jar with small objects and ask: “Are there more than 100 or fewer than 100?” Count together to check. For more practice, try our greater than, less than worksheets and tips on teaching greater than and less than.

100 Days Smarter Certificates

Celebrate every child with a certificate. In our certificate maker, type your own award title, such as “100 Days Smarter,” and print one for each student with their name.

100th Day Words and Printables

Words to learn: hundred, ten, count, group, more, fewer, estimate and celebrate. Turn them into a puzzle with our free word search maker.

Celebrate How Much They Have Grown

The 100th day of school is a joyful reminder of how much children learn, one day at a time. Find more ideas for number sense in our math activities and more celebrations in our seasonal activities.

More teaching guides for January and February: MLK Day, Groundhog Day, Lunar New Year, Black History Month and Valentine’s Day.