Building Number Sense in K-1

building to 100


Number sense and mastering the 100's chart are such important skills for K-1 students.


When I taught 5th grade, I was amazed by how many of my students were unable to jump ahead 10 or 20 without using a 100's chart. I knew I wanted to make understanding the patterns of the 100's chart a focus as a Kindergarten teacher.

I blogged about 100's Activities Tuesday back in my Kindergarten Math Centers series, but I wanted to give you a closer look at what activities have worked so well in my classroom.

I start right away in the first weeks of school by making counting to 100 a huge part of our routine. There are two counting to 100 videos that they love and we watch these every day, during snack and the opening of math.





Both of these songs are very catchy (trust me, you will walk around singing them all day) but very effective. I love using music for academics whenever possible.

We start the first month of our 100's Chart Book the first weeks of school!

monthly hundreds charts


The September page is always a bit stressful for everyone, but I talk about how this is a yearlong activity. By the last month they will be able to see how much they have learned!

monthly hundreds charts

For first grade students, or any student who master this skill earlier, we continue using the template. They just work on the next set of numbers 101-200 or even higher!

monthly hundreds charts

By November, they start getting really competitive and try to see who can get the farthest the quickest!

I usually give them about 5-10 minutes in the first trimester, and then about 15-20 minutes in the second. There are a few students who will struggle with this.

I keep all of their previous charts filed together. This allows me to pull them out at these moments and show each student at all the progress they have really made so far!

monthly hundreds charts

At the end of the year, I put them in order from September - June and add a cover. They love to sit and talk about what they notice.

I do have a few kids who will try to "cheat" and go back and add numbers in. I remind them that this book shows growth and they should be proud with how far they have come. I have also been known to hide the pens and pencils at this time. 

dry erase hundreds chart

In between our monthly 100's chart pages we use the dry erase boards I got on Oriental Trading.

dry erase hundreds chart

I love these boards because they are blank on one side, and have the chart completed on the other. This provides an easily scaffolding for kids who need a little nudge.

dry erase hundreds chart

I put these out every Tuesday. However my students enjoyed them so much, that it actually became an option for morning and indoor recess activity!

These boards are awesome because they can be completed independently or as a team!

dry erase hundreds chart

I also put the scaffolded 100's charts for 1-20, 1-50, 1-75 and 1-100 into dry erase pockets for kids who want a challenge!

scaffolded hundreds chartscaffolded hundreds chart


scaffolded hundreds chart

Each morning we add a sticker to our "How Many Days Have We Been in School?" chart. First we  count by 1's, and then when we get to 100th day, we start counting by 10's.

how many days have we been in school door tracker

During transitions and math centers, they will grab a pointer and practice counting on their own or with a team! 

how many days have we been in school tracker

I already stopped by Michaels to get the stickers for next year's chart!

stickers for tracking days of school

For our math opening on Tuesdays, we sit in a circle and count to 100. Each student says one number and if they do not listen closely they will miss their turn or make a mistake. Whenever that happens, we start over!

Eventually it gets too easy, so we start skip counting by 2's, 5's and 10's.

build to 100 game

After our counting warm-up, we practice building parts of a 100's chart. We start with 1-25 for the first month or two. Everyone gets 1 or 2 cards and has to watch for their turn to "build" it into the correct place in the hundreds chart.

build to 100 game

I make a point not to mention anything about the different colored cards. I like to let them discover all the hidden patterns on their own!

We move onto 1-50 by the late fall. In the winter we work on 1-75 and eventually they are ready for 1-100!

build to 100 game

Whenever I need to get them up and moving during math is when these cards will appear. I write numbers on 12x12 piece of scrapbook paper.

Then, I spread these numbers all over the floor of the classroom, in a mixed up order of course!

I use choose one student at a time to find a number. In the beginning we start small, with just 0-10. But as they advance, we make it harder.

number gamesnumber games


number gamesnumber games

When we are done, we put the numbers in order on the rug. Sometimes it is a set of numbers by 1's, or even 5's and 10's!

Last up is one of my favorites. For 100th day this year, I purchased these star floor clings from Oriental Trading.

count by ten decalscount by ten decalscount by ten decals


As they entered, they had to hop and count their way to 100! We keep these up for about 2 months,  to reinforce counting by 10's, and by the time they were worn out, everyone had mastered this skill!


count by ten decals

Want to see more from my Kindergarten math series? Start with this post!

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