Math Links for Week Ending Oct. 16th, 2015

So Desmos seems to continue to take the math world by storm. The fact that they have created a primo graphing calculator wasn't enough but you have seen it here that they have used their API engine to create the Teacher.desmos.com activity site but then not stop there. One of those activities is Custom Polygraphs, the "Guess Who" like game and more recently they have also created the Desmos Activity builder. Both of these last two are fully editable by teachers and I am happy to say that teachers are both building and sharing these activities. So for example, @marybourassa has just shared one created (or more specifically two) on activity builder dealing with quadratic transformations. These are basically interactive (via Desmos) slideshows that teach a concept.
And as a testament to that sharing Mary has pointed out the Desmos Activity Bank where anyone can share their Desmos based activities. This is a searchable database that has over 130 activities already. I had a quick look and there is some cool stuff there. Like this one from Tony Riehl and John Larsen where they have somehow incorporated a feature where the entire graph is blocked out except where a moveable magnifying glass to reveal any part. Very cool.
Curriculum Tags: All
http://marybourassa.blogspot.ca/2015/10/quadratic-transformations.html

And if that wasn't enough @mjfenton just built this awesome Polygraph for characteristics of histograms. This didn't look easy to build as histograms are not a common graph made with Desmos but clearly with a bit of effort and ingenuity, it is possible (at least for these purposes). To me this is the great thing about how people share. Here Michael has just saved anyone who uses this a tonne of time by building this. Nicely done and perfect for any data management class. 

Curriculum Tags: MDM4U

http://reasonandwonder.com/hello-again-and-histograms/

I have posted a couple of older Geometer's Sketchpad files this week. The first one is a really simple file for practicing the concept of the line of best fit. The file generates a random set of closely linear points and you have to drag a line to represent the line of best fit. You can click a button to randomize the points for a new set and there are Easy, Medium and Hard settings. And remember that if you don't have a copy of GSP but have an iPad, the GSP app is free and it works fine.
Curriculum Tags: MPM1D, MFM1P, MDM4U, MAP4C

The second one is one of my very first "big" sketches. It is multipage sketch that has students first describing one dimensional motion the showing how several motions in one dimension can combine to create motions in two dimensions (this time circular). It incorporates vectors and even some changing rates of change.
Curriculum Tags: MCV4U

And another one of those "problem that stumped the world" posts that show up on your Facebook feeds. This time it's that optimization problem from Calculus of what is the quickest path when you have to cross water and land.
Curriculum Tags: MCV4U
http://gizmodo.com/can-you-solve-the-math-problem-that-stumped-most-scotti-1735604246

I love Ironman Triathlon and I love large data sets. So this is the best of both worlds. Last week was the World Championships and you can get all of the results in one large spreadsheet here. They have done their own analysis but best of all they have made the entire data file available for anyone else to look at. You can get a flavour of the types of analysis you could do but I would start with averages, dot plots, hisograms and box plots on the times for the various sections of the race.
Curriculum Tags: MDM4U
http://www.coachcox.co.uk/2015/10/11/ironman-world-championship-2015-results-and-analysis/

Some nice teaching videos and explanations here about types of data, and single variable analysis of data. Several videos and good written explanations of issues on the blog post.
Curriculum Tags: MDM4U
https://learnandteachstatistics.wordpress.com/2015/10/05/boxplots/

This may seem obvious to a math teacher but maybe not to the lay person. And Martin Gardner really showed it was true. That is, recreation mathematics is good for us.
Curriculum Tags: All
http://www.nytimes.com/2015/10/12/opinion/the-importance-of-recreational-math.html?_r=0

I finally had a chance to watch this and although it is not super dynamic, there are a lot of interesting ideas and examples of problem solving tasks. At the very least, the title alone is intriguing: Developing Mathematical Reasoning and Problem Solving. I like the bit at about 33 minutes about how students think about comment only grading. Thanks to Michele Cooper for this one.
Curriculum Tags: All
https://vimeo.com/118396639

Professor Malcolm Swan (University of Nottingham): Developing mathematical reasoning and problem solving from Mathematics for Life on Vimeo.

"FOILed Again!!!" Can't get enough of a good meme. Thanks to Mark Esping for this one
Curriculum Tags: MPM2D, MFM2P
https://www.facebook.com/PiMathAddicts/photos/a.318224865041690.1073741828.318220011708842/410220642508778/?type=3&theater