UPDATED!! After this post went live last night, I had some fantastic feedback and thought I would make a few revisions. Andrew Stadel (Divisible by 3) suggested that I reverse the direction so that 1 is in the right hand column more like a coordinate plane. What a fabulous idea!! SO…below you will now find those links instead of my original ones!
I bet you are wondering what this post is all about! How could I possibly turn your math world upside down? As elementary math teachers we tend to use hundreds charts to help students see patterns as well as a math tool. Most of you probably use a traditional 1 to 100 chart or a 0 to 99 chart. My complaint about the hundreds chart has always been that when you start using as a tool to teach patterns in adding and subtracting, well it seems to be visually backwards…
Think about it…on a hundreds chart if you add 29 + 10 you start on 29 and go DOWN one line to find a sum of 39. Moving down feels like taking something away not adding to something. The same is true when you subtract you are actually physically moving UP! No wonder our kids are so confused!!! Think about this…on a graph 0 is at the bottom of the graph or on a coordinate grid and the scales moves up. The same is true for a thermometer.
So, why do we do this to kids. Why not turn that chart upside down???? Check out the image below…now add 29 + 10 again. Notice that now you move up, just like a graph, or a thermometer. I just ask you to think about it. I know that you’ve probably been using that traditional chart forever but maybe this might help our students.
To get you started I am giving you some links to some basic Upside Down Hundreds Charts I have made.
Let me know what you think of this! I’d love some feedback…do you like this idea, not like this idea, or if you try it out I’d love to hear how it worked!