# Desmos Redux

We had a productive workshop today, identifying and developing materials for using Desmos — primarily, but not exclusively, in Algebra 2 and Precalc 2.  There are at least two different ways to use Desmos: as a graphing calculator that’s much better than the TI calculators (especially for regression), and as an interactive teaching tool:

• The former is something that we have been doing more and more over the past couple of years, and it only continues to get better. Its great, but it’s not a game-changer. As with the TI calculators, it lets the student focus on big ideas and important procedures without getting bogged down in calculation and algebra errors. No one is saying that calculation and algebra should be avoided, just that there are times to practice those skills and times to pay attention to other ideas.
• The latter, which does have the potential of being a game-changer is best exemplified by looking at teacher.desmos.com and student.desmos.com; these work together to create a classroom in which students explore concepts for learning new ideas, reviewing, and/or practicing what they already know.

One important discovery we made was that we can make good use of Desmos without reinventing the wheel. In particular, there are already quite a few “good enough” activities on the site that cover a full 75% of our Algebra 2 curriculum! When I say “good enough,” I mean that if we spent a reasonable amount of time developing our own activities for these topics, we wouldn’t create anything better. So we brainstormed and wrote activities for several other topics, and it looks extremely promising. In particular, Desmos lets each student in the class work on their own sequence of problems, while the teacher’s computer can show everyone’s work either for individual monitoring or sharing results with the class.

The image at the top of the page shows one example: a real-world time-lapse photo of shooting hoops, together with a general equation of a parabola in graphing form, with sliders for the three parameters and the capability to alter the values of the parameters until the parabola matches the path of the ball. Will the ball go through the hoop? It’s fairly easy to tell. This task is embedded in a larger activity, in which the student sees a variety of photos without equations and graphs, and has to predict whether the ball will go through the hoop. The larger context provides an opportunity for exploring the effect of each parameter.

I will report back later on how well this all works…

Categories: Math, Teaching & Learning, Technology