Sunday, February 24, 2013

Fractions Day 12--Equivalent Fractions Example/Counterexample

Happy Sunday, Everyone!

I woke up to a big surprise--my Skittles "Freebie" was featured in the TpT newsletter!  It has already had over 6,000 hits today!  Crazy!

Today I want to share an activity that I did last week that I feel was a great review of equivalent fractions AND a great opportunity for students to practice their problem solving and their mathematical language.

Here's what we did!

First, I prepared six "posters" with a common fraction on each (If you need a different number of groups, just make a different number of posters . . .  I wanted 3 or 4 students per group).  I made a 1/2 sheet direction sheet for each and placed them around the room.

I reviewed the directions with my students and made sure everyone was clear.  In a nutshell . . .
  • They would get about 4 minutes per rotation.
  • They needed to write 3 equivalent fractions on their poster ("examples") and one COUNTERexample.  As a team, they needed to decide how to create a counter example they felt might "trick" the next group.
  • After their 4 minutes (or so--I watched the groups and moved them when it seemed like they were all ready to go), I rotated them to the next poster.
  • When students get to their next rotation, they need to hunt and find the counterexample and neatly "X" it off.  They then need to work together to find three NEW equivalent fractions and one new counterexample. . . no repeats allowed!
  • After 4 minutes, we rotated again and repeated the process.

The students worked REALLY well together . . . did lots of pointing, used lots of scratch paper, and got super excited about finding counterexamples they thought would fool their classmates.  Overheard . . .

"If we make the numerator and denominator only one off from the original, it might fool them!"

"I think the last group made a mistake with this one--I can prove it!"

"This one can't be equivalent to 3/4 because it isn't even close to 1/2!"

As you can see, students had to really apply the understanding they have been building over the last few days . . . and I think it paid off.  When I gave them a more "traditional" exit slip the next day, only two students didn't show excellent understanding of the concept!  

When we were finished, I put them together and hung them up on our fractions board . . .

Later that day I noticed students stopping by to check it out and to see what other fractions students wrote down.  I think this activity could have lots of other applications in math!  

Thanks for stopping by--and have a great Sunday!


  1. Another great lesson, thanks!

    And congratulations on having your fraction product featured! I was so excited for you :D

  2. Thanks Amber! It was a pretty exciting email to open up! :) I hope you had a great weekend...

  3. Such a good idea - I'm saving all these ideas for when we start fractions again :) Love this poster idea!! 6000 hits?!! That's awesome!!


  4. I ADORE this idea. What a fantastic and simple lesson. I know my students would love this!

    1. Glad to hear it Dawn! Let me know how it goes...