Last weekend, I attended the California Math Council’s annual CMC-North conference at Asilomar State Park, near Monterey. This is my favorite of all the conferences that I’ve attended, and this year (my 13th time in 15 years of teaching) may have been my favorite so far. Although there were some big math celebrities that didn’t make it this time (Dan Meyer and Jo Boaler come to mind immediately), I made a lot of connections through Twitter. Yes, I have finally really started to “get” Twitter (Follow me: @Ethan_MidPen, if you aren’t already, to see more of my thoughts on math, math lessons, and math education), and have started using it to communicate from a number of great math teachers. I also was opened up to the amazing things that http://www.desmos.com can do – not just be an online graphing calculator (although that’s nice), but it can be a platform to open the classroom up to all sorts of amazing and fun ways to explore math. This past Monday morning, they released a new activity called “Marbleslides”, and it took up all my free time this past week. I showed it to my 6th period Trig class at the beginning of the period today, and most of them, after seeing the first 3 slides, copied down the link. I’m pretty sure some of them will be even more proficient at parabolas by the end of winter break, and will be ready to play the trig functions Marbleslides as soon as I show them.