I Cannot Think When Cheetos are Present

I wanted to make a quick post to remind my future self how the Mathalicious lesson Cheese that Goes Crunch went this school year & how I should adapt it for the future.

The purpose of this activity is to have students develop a method to relate cheesiness to the non-cheesy portion of a crunchy vs puffy Cheeto in order to develop a measurement of which is cheesier & by how much. It is a realistic application comparing surface area to volume.

I have 3 sections of geometry, so I attempted this lesson 3 times, each a little differently – and I’d do this lesson again next year, but with more changes.

In my first class I made a fatal error – I distributed cups to the students and then ran around the room with a giant bag of Cheetos pouring them into each cup. This turned the class into a party. Students sat with Cheetos while not working on anything. BIG MISTAKE. When I tried to engage the class in the lesson there was little buy in or understanding of the goal of this activity and I ended up dragging my class through each component of the activity. While it was completed in the end, it was not understood by students.


For my next two classes, I set up cups with crunchy & puffy Cheetos in advance and set them out of sight. I introduced the activity and had good discussion and student ideas of which type of Cheeto was more cheesy and why. I didn’t provide them with Cheetos until they had a plan for determining which one was more cheesy and they concluded that the cheese was around the exterior, so the needed to compare surface area to volume.

I also found it pretty amusing how many students felt the need to organize their Cheetos:

2015-04-09 09.40.11 2015-04-09 09.42.54

Overall the activity was a great way to have students apply volume and surface area to a context. Next year I will make this task run more like a 3 act and less like a guided worksheet. I don’t want to tell the students what to think and when. It’s too helpful to tell them to approximate each Cheeto as cylinder and guide them to find the surface area and then the volume, and then find a ratio. Students don’t have the same degree of curiosity and satisfaction compared to them deciding what they need to do themselves.

This lesson took one 45 minute class period, but If I make these adaptations for next year It will most like take two: One period for the initial student question development and calculations and a second for student presentations and possibly time for them to improve or reflect on their work. OR maybe a gallery walk and whole class discussion.

I’ll adapt it like this next year:

Act 1 will beg the question of which type Cheeto has more cheese flavor. I will work through a notice/wonder and develop a main question.

Act 2 will be students determining what information they needed and equating a serving of crunchy Cheetos to puffy Cheetos. Then finding the volume and surface area of an average Cheeto and developing and justifying a method to measure cheesiness.

Act 3 will include student presentations of their analysis effectively sequenced as described in the 5 Practices book and maybe a reveal of how much more cheese powder per volume there are in crunchy vs puffy Cheetos (although this may not be necessary).

This task is a great idea and is worth doing with students. I think I struggled with its implementation because I did not develop enough student buy in and understanding of the question from the start – which I continue to be reminded is a critical component to successful student problem solving.

After a year of teaching Programming with CodeHS

I started teaching programming for the reasons that I mentioned here. I felt pretty clueless about how it would go and I didn’t know exactly how I would even grade students after the first few weeks of the class had passed.

Things I’ve noticed:

  • Similar to Khan Academy, using CodeHS alone and expecting students to work in isolation is dehumanizing and will teach them very little. One of my primary reasons for teaching programming is to help students feel confident taking risks and being creative. Michael Fenton’s Ignite talk sums up this comment better that I can.
  • Students do not look at and think about examples. They just don’t. They have to interact with it for it to be useful.
  • Most of the CodeHS instructional videos begin with a brief explanation of a new coding concept, then go on to write a program using the concept. I’ve learned that that first minute is beneficial, then I stop the video.
  • Some of the units progress a little too quickly, leaving students feeling very under-equipped to write programs. I felt the same way when I completed the unit myself – particularity sections of the JavaScript unit.
  • Some of the programs students are asked to write could be more engaging. For example, they write a program that decides if it is a weekend, there are a few programs that discuss apples & oranges.
  • The instructions for each program could be explained more clearly. A 10 point font paragraph is tough for some students to follow on a screen. A bulleted list of expectations for the programs, or a checklist would be even better: where students check off when their program is able to complete each component.
  • It is missing a projector mode where I can project a complete program with a large, bold font.

What works for my classes

I anticipate areas where students will struggle and develop activities to bridge the gap. These activities include:

  • Modifying the example programs to do something similar, but different then what they currently do. This is much more productive then having students watch the program being written in a video.
    • Some examples:
      1. Change the example program that converts US dollars to GB pounds to instead convert minutes to hours.
      2. Change the example program that draws a blue circle to draw 1 large circle centered exactly on the canvas, and change the color.
      3. Change the calculator example to instead prompt the user for how much money they waste per week and calculate how much money they waste per year.
  • Pencil & paper activities that allow students to think through a challenging coding concept and better understand the computations behind the code. Here is an example of an effective activity to help students understand how for loops can be used to sum numbers:

  • I employ the concept behind the 5 Steps to Orchestrating Productive Math Discussions with students programs:
    • They attempt & submit their programs
    • I pre-select and sequence their programs
    • Student present their code as the class completes a form keeping track of each program and their observations:Capture
    • Students discuss and compare different approaches their peers have to complete a specific program.
  • Minimum lines of code contest: especially at the beginning of the school year, I’ll tell students that we are having a contest today to see who can make their program work using the smallest number of lines of code. This encourages them to think about programming efficiency and style and not just accomplishing a task.
  • Students get choice in a final project for each unit. There is a separate part of CodeHS that includes “supplemental material” I used these and assigned a point value to each program and told students they just had to earn 30 points. some students opted to complete 1 challenging program while others completed many more simple programs.


  • I currently grade with 70% or their grade being successful completion of each programming unit (for loops, variables, booleans…), 20% of their grade is their final project for the unit, and 10% is supplemental practice, worksheets, etc.
  • I’m not thrilled with this system. I keep edging closer to eliminating grades in programming, but I’m not quite ready yet. Maybe after some serious consideration this summer.