Monday, October 3, 2016

Building Fraction Sense

The struggle here is real.
A student has no idea where to place a fraction on a number line (because fractions aren't numbers, of course) but can convert to a mixed number like a champ.

My attempt to help out:




This applet gets at the heart of the things I've enjoyed working on lately.  The initial estimate offers very little help, but as the student progresses through, they have more references which allow the revisions to become more precise.  When my students worked with this applet, there were audible groans when I asked them to lower the lids on their computers as well as exclamations of "I got it!" when they moved closer to 0% error.

Here's a GeoGebra book that goes from estimating fraction to addition to multiplication.  I'm still working on division, but that should drop soon.

4 comments:

Tommy Lingbloom said...

This is really great David! Thanks for taking the time to develop this. There are a lot of little fraction apps out there but I really appreciate the coherence piece of what you've put together here. Well done. I wish I saw that longevity of concept more frequently.

Chris Kunkel said...

Hi, I like the idea. Not sure %error is the right thing to display though. You can be closer in an absolute sense with smaller fractions yet get larger percent errors. While accurate in a strict sense, not sure kids would get that. Maybe just show some absolute deviation so the size of the fraction you are estimating doesn't affect your error.

Sue VanHattum said...

I love this. Thanks.

David Cox said...

Chris,
I tend to agree with you here. I think when I first started these apps, there was a reason I used %. To he honest, I don't know what it was. Perhaps I'll go back and fix it, but I don't think it's critical to the concept.