The year I taught 1st grade, we planned a blowout mathematical bash to celebrate the 100th day of school. When I switched back to teaching upper elementary, a similar 100-hoopla didn’t feel like a match with my students’ mathematical development. According to the Common Core State Standards, 1st graders are expected to compare, count, and decompose numbers within 100, and 2nd graders are expected to understand place value through the thousands. How could I make the 100th day of school jibe with upper-grade math standards?
(For suggestions about how to celebrate the 100th day with younger students, see fellow blogger Tiffani's post with more than 60 fun-filled ideas.)
Back in 1st grade, the 100th day of school allowed my students to embrace the artistic side of math.
Taking a broader view of the significance of 100, I use the week surrounding the 100th day of school for a mid-year review of place value concepts. Working with decimals, millions, and bases other than ten, my students revisit the place value concepts we explored at the start of the year, this time with more complexity. Here are five enriching activities to celebrate place value for the 100th day of school, or any time!
In upper elementary school, an important understanding is the changeable nature of “the one.” When we first introduce place value concepts, we teach that the units-cube is worth one; however, older students need opportunities to explore variations on this model.
My students enjoy drawing pixelated versions of their names, using mini hundreds grids to represent one whole. (This activity could be adapted for younger students, skipping the decimals connection and using each grid to represent 100.) This activity page includes 12 grids for writing letters, as well as directions for completing the name plaque project.
Just as it is important that younger students have mental models for the relationships between ones, tens, and hundreds, older students need mental models to cement their understanding of larger values. This activity helps my students deepen their understanding and build a mental image for “one million.”
Working in teams, each student receives a ten thousands grid. I first ask them to find and color a square worth 100. Then the students color in 10 hundreds-squares to shade 1,000. Building on this, the students discover that they are holding a ten thousands grid. I ask the class, “How many ten thousands grids do you need to make one million?” Then I ask them to work with their teams to create a “millions quilt.” The most valuable part of this activity is the discussions the students have as they work together to answer the "One Million Quilt" questions.
After taping together their One Million Quilt, the students discuss and chart their place value discoveries.
Older students claim that they know the hundreds grid through and through, but can they recognize and apply the grid’s patterns without relying on familiar numerals? The mathematical wizards at Cambridge University’s NRICH project have created a thought-provoking puzzle with a coded hundred square. After my students have solved the puzzle, I ask them to discuss the patterns they discovered and write an explanation of how these patterns relate to our number system.
To extend this activity, I have students make up their own coded hundreds squares, using nonsense symbols to represent the digits 0–9. Students can do this by hand if you print out the first page of the activity template. Better yet, my students enjoy making their own coded grids on the computer using the wingdings and webdings fonts to choose interesting symbols. It’s not until the students design their own coded hundreds square puzzles that the room fills with a chorus of “Oh, I GET it!”
The students cut apart their finished coded squares to create puzzle pieces and store their homemade puzzles in zip-top bags for other students to try. For hundreds grid puzzles with regular numerals, check out these puzzles from Mathwire.com or cut apart regular hundreds charts for students to reassemble.
Students build a much deeper understanding of what place value really means when they venture outside of our decimal number system, so while this sounds like “smarty-pants math,” I encourage you to give this a try with your students. When students explore bases beyond base ten, they understand why we have exactly ten digits, the exponential relationships between place value positions, and what “grouping” is really all about.
A student's first attempt at base five, using place value "blocks" to build the understanding.
Nostalgic for the “good old days” in the lower grades (last year?), my students often want to do a 100th day of school activity that is less about place value and more about celebrating 100 — and just having fun. To stretch their creativity and provide the longed-for 100 activity, I invite teams of students to choose a topic that they can expound upon in 100 different ways. Then I set a timer and the students race to brainstorm 100 countries they’d like to visit, 100 acts of kindness, 100 great books, 100 personality traits, and more.
Do you celebrate the 100th day of school in your classroom? How do you make it meaningful for upper elementary students at your school? I’d love to hear your ideas!