Happy first day of October! This post is about an assignment (or “performance task”) I did in my Grade 10 math class last year. It could be done as an in-class activity without evaluation as well. It is based on the following expectation from the Ontario Grade 10 math curriculum:

Collect data that can be represented as a quadratic relation, from experiments using appropriate equipment and technology or from secondary sources; graph the data and draw a curve of best fit, if appropriate, with or without the use of technology.

Like with most lessons, I started off by looking at what other teachers who had taught the course had done before. In the past, students used imprints of their molars, which fit a quadratic model quite well. They used TI-84 graphing calculators to model the set of the points created by the imprints, which were done on graph paper.

I wanted the task to be a bit more open-ended. I am not a huge fan of TI-84s, so I decided to use Desmos instead. I decided to combine the quadratic modelling with a task my host teacher told me about when I was a student teacher, where students used iPads to do a parabola scavenger hunt around their school and online. Technology-wise, I was teaching at a 1:1 school, so each student had a laptop they could use for the task.

Onto the assignment: students were asked to find or take a picture of a parabola and upload the picture to Desmos:

I demonstrated how to enlarge or shrink a photo on the screen, and how to move it so that the parabola is symmetric about the y-axis. The next instruction was to estimate 10 points on the parabola as accurately as possible.

Then comes the cool part: **Desmos has its own quadratic regression model.
**Yes, it really is so cool. With this one line of “code”, you can easily do your own quadratic regression on any set of points:

I had students fill out a table to find similarities and differences between their model and two friends’, instructing them to use parabola vocabulary that we had talked about in class (opens up/down, vertical stretch/compression, etc).

Here are some examples of what my students came up with:

Overall, it was a good day: it was a light, fun activity for the students the day after a test, and it was easy and fun to mark.

If I were to make any changes the next time around, I would have the rubric reflected as a mark out of 10 for each achievement category, where each level is converted to a percentage. I would also try to match up the rubric language with the language that the math curriculum uses for assessment to make it more student-friendly (page 20-21 here).

The full assignment is available here: QuadraticsIIIPerformanceTask

(If you don’t feel comfortable downloading from online, shoot me a message in the “contact me” section and I’ll send it to you by email.)