The teachers I coach are beginning their investigation of exponential functions. They are using Core Plus Math, and are working really hard to do increasingly problem-based, student-centered teaching. I’m helping the teachers with pacing, lesson-planning, and formative assessment, as well as coaching them on facilitating student-teacher and student-student interactions.
So… my project over the break is to put the “fun” back in exponential function (and maybe put a little “expo” back in there too). “Why do we have to learn this? What matters? What does this have to do with what we already know?” are valid questions I hope students ask and I can help them answer. (By the way, I just learned that exponential functions can help us predict when everyone on earth will be following Lady Gaga on Twitter (October 2025), but I don’t think we even need such fascinating applications to help make sense of exponential functions. Source: http://www.youtube.com/watch?v=51AhdTj-irQ&feature=youtu.be)
What’s the big idea behind exponential functions? And what experiences help kids ask the big idea questions themselves?

