## Wednesday, April 13, 2016

### Day 137: Sub Day: Descon 2016

Today I went to a NCTM pre-conference at Desmos, dubbed Descon 2016. My 8th graders worked on writing and solving equations of angle relationships and graphing relations and deciding if they were functions. In accelerated students practiced solving inequalities and graphing the solution. They also practiced graphing linear inequalities as well as a couple systems of linear inequalities.

I took BART to the conference. I shouldn't have got my own Starbucks because they already had a ton of coffee. After 30 minutes of socializing Dan Meyer introduced the agenda. We split up into beginning, intermediate, and advanced groups to try to replicate some amazing Desmos calculator demonstrations. I went to the intermediate group and we worked on reflecting a movable point over a movable line. We tried not looking at the code that JJ used to make it.

It was great to meet math teachers in real life that I have talked to on Twitter. Chris Danielson, Dan Anderson, Max, Peg Cagle, Michael Fenton, and many many more.

After that we had lunch that was catered. Some delicious garlic noodles and ban mhi sandwiches. Then Phil Daro gave a talk about math instruction in America being a mile wide and inch deep.

After the keynote, Dan introduced a basic Activity builder activity for those who hadn't used it before. He discussed how it was created, and also previewed a brand new feature of card sorts that will make it into the features later. In the afternoon session, we broke out into middle school, algebra 1, and upper high school math groups.

Christopher Danielson lead our group and we worked through Jon Orr's awesome Sugar Sugar activity about predicting how sugary a selection of cereals were. Then we duplicated it and looked at how he programmed it. Then we brainstormed what types of activities we were interested in making that hadn't been made yet. My ideas were: identifying if a relation was a function, making a 2 way frequency table, and estimating irrational numbers to the nearest tenth. The first and last activities I introduce with notes, so it would be nice to make a digital version, as long as it has benefits over the paper and pencil version.
 Christopher Danielson, the author of this book signed my copy for me!
 I met Michael Serra, author of Discovering Geometry. Ms. Wong used his book and has worked with him before!
 Here's what the headquarters of Desmos looks like. Quite a big group!
 In the smaller conference room we dug deeper into activity builder.
 Here are some tiling snowflakes. I think they have another name, I forget what it is.
 A bigger size with a yellow 3D printed puzzle on top.
 Christopher made this shape with the trapezoids.

 I almost made a complete shape here with the smallest trapezoids, it was just too hard to keep them tight when they're so small.
 Almost a pentagon with these other trapezoids.
 These were made out of acrylic. Very fun.
 Dan Anderson made these with a program from a Wisconsin Professor and a 3D printer. On the left, the top layer is a triangle, with a square, then a pentagon and so on below it. The sides are all congruent. Looks so cool. Also, on the right is a problem called the dog chase where the square keeps getting smaller and thinner and gets a slight rotation.