Number Line versus Hunderds Chart

Sep 20, 2015

Our guided math groups finally started!

As we looked back at how we started last year, Jess and I decided upon a couple of goals for our first two weeks of math groups this year:
1. estimation
2. number lines
3. hundreds chart

As our planning unfolded, we also decided that it was very important for our students to understand the connection between a number line and a hundreds chart.  They can seem like such separate tools and resources; however, we really needed our firsties to understand how they connect.

 Our firsties have seen and used a hundreds chart in Kindergarten.  They have also seen them hanging around the room.  They could even tell me that the numbers do "get bigger" as you go down the chart.

Okay...that is completely a start.  But Jess and I wanted to help bring this chart "to life" a bit more for our little learners.

So we cut it up.

 We cut along each horizontal line of the chart and then taped it together.  This left us with one big long number line.  Their mouths dropped open.

I'm not kidding.

They were stunned that this hundreds chart was really just a big number line.

Then we used the big number line to plot some estimation jars that we were also using.  We used it to count.

But there was a problem.  It didn't fit on our table.  It was so....long!
This led us to our next discussion point...the number line is a great tool but a little hard for us to store because it won't fit in the desks or on top of my table.

And this is about where our lesson ended...until the next day.

When our firsties walked in the next day, they quickly remembered what had happened to the hundreds chart.  It was really just a number line.  And we used this tool again to help us with some estimation jars.

 But that number line STILL would not fit on my table :)

So I asked them if it would be okay if I tried to make it into a tool that would be easier to use at our table.  I showed them that I could wrap the number line around a tube.  When I did this it allowed me to fit the whole number line on my table. (The idea came from an image I saw from "What I Have Learned").  It turned out like this:

As a group, we tried out this new resource.  Was it really still a number line?  We counted with it.  Yep.  They numbers still grew as we went down the "tube".  Were the numbers still in the correct order?  Yep.  Then I did something crazy!

I cut it.

When I opened up the tube, their mouths drop wide open!  It was a hundreds chart.

Our lesson had come full circle.  We started with a hundreds chart.  Turned it into a number line.  Took the number line and turned it into a hundreds chart.

They saw the connection.  The number line and the hundreds chart are made up of the same numbers.  They are just laid out a bit differently.

It was a good moment.  Jess and I felt like it kicked off our groups in a positive way.


  1. Ummm, hello fabulous!! I couldn't wait to see what you did next as I read. What a fun lesson :)


  2. Oh my!!!!! This is a game changer... I'll keep you posted.


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