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The 100th Day of School and Number Sense

The 100th day of school is a day to let your imagination go wild! Celebrate the day with collections of 100 objects, counting activities, and lessons that dig into the physical meaning of large numbers and how they are represented. You can also explore the theme in art projects and in social studies and science lessons as well as making the wonderful literature connections suggested below.

Here are a few ideas to get you started:
• Ask students how many dimes, quarters, pennies, or 50 cent pieces make a dollar.
• Read the class I'll Teach My Dog 100 Words, and then have the class write its own version—I'll Teach My Cat (or bird or the animal of your choice) 100 Words.
• Make a class list of the students' favorite 100 books, or 100 books they have read.
• Have students collect 100 cans of food to deliver to a food pantry.
A good way to conclude the day is to have students figure out when the next 100th day of school will occur and mark it on the calendar.

In the lists of resources below, you'll find hundreds of other suggestions for using everyday objects and readily available books to deepen students' understanding of numbers when counting, estimating, calculating, and making sense of the world.

From the ORC Collection

## Lessons and Activities

Ten Frame (ORC #13663, grades K–2), an interactive, online game, features four activities designed to develop students' counting and addition skills. Students count and identify how many items or empty spaces are in the ten frame. They fill empty spaces with circles, bugs, stars, or apples and drag items to complete simple addition problems.

Concentration (ORC# 13606, grades K–6) features six interactive, online activities that involve matching equivalent graphic representations to numbers, geometric shapes, multiplication facts, or fractions and percents. One or two students can play this matching game at their own pace to either practice facts or reinforce their understanding of mathematical representations.

In the Number Cents (ORC# 1133, grades preK–2) unit, students explore the relationship between pennies, nickels, dimes, and quarters. They count sets of mixed coins, write story problems that involve money, and use coins to make patterns. Readings from children's books relevant to this topic enhance each lesson.

In the first of two activities that focus on number patterns, Displaying Number Patterns (ORC #1439, grades 2–4), students work with virtual hundred boards and calculators to highlight and display patterns and relationships among numbers when skip counting. In the second activity, Patterns to 100 and Beyond, students skip-count both forward and backward starting at various numbers. Students can move beyond 100 and below zero using just the calculator.

## Student Bookshelf

 Counting Our Way to the 100th Day! by Betsy Franco contains 100 charming, illustrated poems that engage students in thinking about numbers in fascinating and unusual ways. This book will delight readers of all ages. The clever rhymes and colorful illustrations in 100 Days of School by Trudy Harris will intrigue students as they think about addition combinations for 100 objects. 100 School Days by Anne Rockwell is the story of a class marking each of the first 100 days of school by putting a penny in a jar. For days 10, 20, 30, etc., one student would be assigned to bring in a collection of something with that number of objects. On the 100th day everyone brings in 100 treats to share with the class. Appealing small animals and the idea that numbers are friends make Emily's First 100 Days of School by Rosemary Wells fun to read. Students will enjoy counting along as the number of days and collections of objects grow from 1 on the first day of school, to 52, represented by the 52 cards found in a deck of cards on day 52, and on to the collections of 100 objects that Emily and her classmates bring to school on the 100th day of school. The illustrations in Henry's 100 Days of Kindergarten by Nancy Carlson note the passing months from September to February and the growing number of jelly beans added daily to a jar. Holidays are celebrated, and collections of 100 are noted as the class moves through the school year to the 100th day of school and its grand celebration. 100 Ways to Celebrate 100 Days by Bruce Goldstone features 100 great ideas to keep a focus on 100 for the first 100 days of school. The cleverness of the presentation reflects the approach to number sense the author celebrated in Great Estimations and Greater Estimations! These last two books will appeal to readers and estimators of all ages.

## Resources for Students

The online learning tool Can You Say Really Big Numbers? presents an engaging way for students who can read to practice saying and reading any large number that they type into the tool.

Students can use the online and printable Interactive 100 Number Chart (1–100) to skip-count and to find factors and multiples.

See Number & Operations (Grades PreK–2) from the National Library for Virtual Manipulatives for a great collection of online learning tools for building your students' ability to understand and use numbers.

You're an elementary teacher, which means, of course, that you frequently combine subjects when you teach. Here is a suggestion for integrating writing into your 100th Day celebration: Descriptive Writing and the 100th Day of School (ORC #6403, grades K–2).

## Background for Teachers

The ORC Mathematics Bookshelf features information about using outstanding trade books in the classroom. One bookshelf entry, One Hundred Hungry Ants (ORC #11140, grades 3–5), offers an entertaining introduction to division as 100 marching ants are arranged into two rows of 50 ants, four rows of 25, and more. The illustrations and math patterns make this book a fun one to read with K–2 students.

On Joan Holub's 100th Day of School Website: 300 Celebration Ideas for Educators, learn about the possible origins of celebrating the 100th day of school and see 89 creative ideas for celebrating the day while reinforcing basic mathematics skills such as estimating, counting, measuring, and sequencing.

Suggested Activities for the 100th Day includes songs, poems, and other creative ideas for celebrating the 100th day of school.