The Great Ozobot Perimeter Race!

             As time has gone by this year, it has become apparent that my students respond well to the programming opportunities that they have been presented with.  While building their understanding of area and perimeter, it was time to revisit my very first Ozobot lesson.  I created this lesson about a year ago.  This year, with the development of the Ozobot Bit and the Blockly programming language, it would extend even further!

The Challenge:

          Students were given the sheet below and  grid paper for planning out the possible perimeters for the given area.  Students did steps one and two on their own and support was given as necessary. 

You can download a copy of the lesson plan by CLICKING HERE.

The Process:
            Students took their planning seriously and worked to figure out all of the possible dimensions for the area of 32 units squared. Below is one example of the kind of work the students produced. 

           From there, they worked to calculate the various perimeters.  Sharing their findings with a partner, they decided which perimeter would be optimal for the Ozobot to travel around the most times in 1 minute and 30 seconds.  I asked them to explain their reasoning.

          The next phase of the project had students design and test their Ozobot course.  They drew out the perimeter they thought was the optimal racing track.  Students needed to remember to make the line an appropriate thickness and ensure that there were no lines that surpassed the corners, as those could have confused their Ozobot.

         Most students determined that the 6 by 6 square was the best option.  The students who didn't choose this one came to the realization that their choice was not optimal when testing their chosen perimeter against that of their partner (who had a 6 by 6 square).  As students began to test, they asked if the Ozobots all had the same speed.  Since they hadn't been calibrated, we quickly adjusted that so that we had a control.  Then, testing began and students recorded the number of laps on their sheet and compared with their partner.

This student recorded the start and end positions of their Ozobot.

Extending the Learning:

          This year, with the development of the Ozoblockly coding, it was time to give my students an additional challenge.  I asked them to create a program that would draw out the perimeter of 36 units squared.  The eagerly accepted the challenge!  As they began, some interesting questions arose for discussion.  Do the steps in the Ozoblockly program match the grid squares? How far is one step? Is there a way to program the distance without using steps?

    I was delighted with the critical thinking that was going on and returned their questions with another question... How are you going to figure that out?  

  

This student programmed one step and ran the Ozobot to see the distance.

              Not every student approached the obstacle this way.  Another student discovered a higher level of programming and experimented with mixing the levels of coding to get what he desired. He measured his original drawing and input the data in to the program.  He, as well as many other students, decided to use the "forever" loop in order to run the Ozobot uninterrupted for the full 1 min and 30 second time limit.  Once the program was complete, it was uploaded into the Ozobot Bit and away they went, comparing the results to their original paper course design. 

          Since this was the second year that I have run this activity, it was nice to take it to another level and add in the Ozoblockly programming.  Not only did students develop their understanding that a given area can have multiple perimeters, but they also problem solved to get through the translation of their paper and marker courses, to the Ozoblockly program.