I’m intrigued by the Desmos Activity Builder and where it might be useful for my students.  One of the first activities I’ve made is based on the idea of fitting graphs to photos of naturally-occurring or man-made parabolas, which I first encountered in Adrian Oldknow’s book Teaching Mathematics Using ICT back in 2004.

In my activity, students are asked to fit some parabolas to photos of bridges and fountains.  And a banana.  They are also asked to explain their thought processes before they attempt the graphical transformations.

If you haven’t encountered the Desmos Teacher Site yet, it’s great fun, and really well thought-out.  You can watch what all your students are doing/have done from your computer and target your help and questioning where they are most needed.

I love watching students get excited by graphs (’cause graphs are just wonderful, let’s be honest here) and I love using resources in my classroom, both from the front and amongst the students, that make graphs (“I don’t like drawing graphs”…”I don’t get graphs”) and the principles of graphing more accessible and easier to understand.  I’ve been giving some thought to why Desmos seems to achieve this so well and I think it’s because without having to physically draw the graphs all the time students can spend more time thinking about the principles behind them.  From the front of the classroom I can display a quadratic and show the roots/intersections with axes/vertex immediately and talk about these features.  I don’t waste time drawing the graph (by now I’m quite happy my students can plot a curve), and if I want to change my example I only have to alter a number or move a slider.

Of course, graphing software has existed for a long time, so what I’m talking about is nothing new, but before now I’ve never used graphing software that is so quick and easy to create with and, more importantly, that is this high-quality for free!

I’m starting to sound like an advert now, so I’ll stop, but if you are a maths teacher and haven’t tried it yet, do so soon.