Desmos Polygraph: Place Value


In the spring of 2018, I introduced Desmos to a couple of 4th grade teachers.  After running, Ordering Fractions on a Number Line and Polygraph:  Geometry Basics, they were hooked on Desmos.  During the last days of the year, they asked if I had any Desmos activities that focused on place value.  At the time, I didn’t.  But now I do.  🙂

Polygraph:  Place Value 

Polygraph: Place Value


The first time I ran this Polygraph, it bombed.  I was not expecting such a beloved platform to cause so much distress.  Just last year, I ran Polygraph:  Geometry Basics in multiple 4th grade classrooms with great success.  Then it hit me.  This former middle level math teacher quickly realized that 4th graders in August are very different than 4th graders in May. A lot of maturity and growth happens in the months between August and May.

My Light Bulb Moment

Using the teacher’s computer, I signed in as a student.  When the computer assigned me a partner, I hit the pause button.  I explained that, as a class, we needed to run through a game together. It would be the most efficient way to address all their questions.

To run through the practice game, I had to unpause the activity.  Student computers now had the potential to become a distraction. My solution was to ask all students to turn their computers, so the screen faced away from them.  We quickly brainstormed a list of reasons why we had to reposition our computers. The brainstorm helped students buy into pausing their individual games and playing as a collective group. They were now willing to give their full attention.  Time to play.

My partner picked a card.  The rest of the class and I were tasked with determining which card she picked.  I facilitated the process.  Students provided me with yes or no questions, told me which cards to eliminate and explained why.

The first round was the longest.

  • Our question:  Is your number odd?
  • Response:  No

There are 16 cards and we talked through whether to eliminate each card.  The process of understanding which cards to keep and which to eliminate can be challenging.  It’s important for students to understand how to maneuver the elimination step.  Sixteen different students verbalized their thinking.  This process moved at a snail’s pace at first, then, as students solidified their understanding, it sped up.  Believe me, this is time well spent!!

To exposed students to varied questions and to expand their academic vocabulary usage, I guided their questions.

Examples of question types:

  • Is there a 4 in the hundreds place?
  • Is your number 5 digits long?
  • Is your number greater than 1000?
  • Is your number less than 10,000?
  • Does your number have a digit in the millions place?
  • Is your number even?

Each round moved faster due to a combination of fewer cards and increased understanding of how to play.  When we discovered our partner’s number, the class cheered.  I love to hear cheering during math class.  Music to my ears.

Student were given the signal to turn their computers around and continue playing their individual rounds.  Students were more independent and far less frustrated.

Over the next two weeks, I ran the activity with two more 4th grade classes and a 3rd grade class.  Each time, I ran the activity whole class before letting students play individually. Each time, the individual games ran smoothly afterwards.

Side Note – Third Graders

In my opinion, due to typing skills, the youngest grade I’d use Polygraph with is third.  Any younger, the ability to type hinders the questioning process.

Polygraph: Place Value


About jgvadnais

Instructional Technology Coach. Desmos Fellow. Google Level 1 Certified. SoCal transplant. New Englander at heart. Lover of yoga, dogs, green smoothies and coffee creamer
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