## Friday, May 20, 2016

### Math Links for Week Ending May 20th, 2016

For years I have always talked about the nature of big numbers with my data management students. Every year I had them find a big number and then try to analyze it to determine whether it is really big. For example, here in Canada, recently there was a \$79 million DRAM settlement. But with 4 million potential litigants expected, that means about a \$20 settlement for each person. So this new (to me) site was pointed out to me and it totally resonated with me. Is That a Big Number is a site that takes big numbers and looks for context, has conversion apps and quizzes and facts. Check it out.
Curriculum Tags: Gr7, Gr8, MDM4U
http://www.isthatabignumber.com/

I have certainly spent my time as a traditional teacher but I think that as I age, I become more nuanced. So where I used to be a staunch advocate of the balance method for solving equations as being the Holy Grail, discounting anything else as inferior, now I see the value in intuition. Giving students a more attainable feel for solving equations, I think, is a far better way to start the on that path. So when dealing with one and two step equations, this method of using a double number line is a very neat way to help students truly understand what it means to solve and equation. See how @MrOrr_Geek gives a step by step on how to use this method on this post.
Curriculum Tags: Gr7, Gr8, MPM1D, MFM1P, MFM2P
http://mrorr-isageek.com/double-clothesline-solving-equations/

I like this 3Act task from @mathletepearce on parallel lines and transversals. It has a nice mix of real world (railings on a staircase), notice & wonder and hands on paper cutting.
Curriculum Tags: Gr 7, Gr8, MFM1P
https://tapintoteenminds.com/3act-math/railing-reconstruction/

Some very cool (and maybe gross) data from Five Thirty Eight. apparently it was gut science week and they have many articles on various gut related topics. Of course a fair bit of that is about poop. And if that is not a hook for students then I don't know what is.
Curriculum Tags: Gr7, Gr8, MBF3C, MDM4U
http://fivethirtyeight.com/features/gut-week-introduction/

Some more @desmos Friday Fives. Here are a couple of weeks worth. Some things on slope, domain and range, parabolas, some derivatives, extrapolating with the fastest mile, some intuitive lines of best fit and more (and I love the scatterplots Polygraph).
Curriculum Tags: All
http://blog.desmos.com/post/143605448140/friday-five-for-april-29
http://blog.desmos.com/post/143957961292/friday-five-for-may-6-2016
http://blog.desmos.com/post/144315807437/friday-five-for-may-13

I think I agree with most of what @matthewoldridge says in his unpublished letter to the editor here. The only thing I may contend with is the notion that \$60 million is nothing to sneer at. I will sneer. In light of our featured post this week I would argue that \$60 million isn't much money at all. In fact, it's not even new money. It's redirected money (so other programs are being short changed). And if you work it out, with about 1.5 million gr k-9 students (where the money is targeted) that works out to about \$40 a kid or a fraction of a percent of each student's total funding.
Curriculum Tags: All
http://matthewoldridge.blogspot.ca/2016/05/letter-to-editor-of-major-national.html

Some history here. The story of zero. As it turns out we didn't always have zero to kick around. Here is an older radio piece on zero from @SLsingh too.
Curriculum Tags: All
https://vimeo.com/161757232

The Story of Zero - Getting Something from Nothing from The Royal Institution on Vimeo.

A left over post from OAME 2016. @wheeler_laura has been doing a lot of sketchnoting and I shared some two weeks ago, here she uploads all of her notes from OAME2016 and to go with the Ignite ones are a couple on a session on Assessment from @lkpacarynuk. I love talking about assessment so I was intrigued by what's on these two notes. I kinda wish I was in that session.
Curriculum Tags: All
https://mslwheeler.wordpress.com/2016/05/19/oame-sketchnotes/

I don't know much about Sumo wrestling but this set of data is impressive. It is hard to tell from the image below, but click on the link and see how interactive it is. And if that doesn't impress you, the shear fact that there are hundreds of years of data represented in this set, has to.
Curriculum Tags: MDM4U
http://projects.fivethirtyeight.com/sumo/

A very cool example of rotational symmetry for any geometry class. Thanks to @mathletepearce for this one.
Curriculum Tags: Gr7, Gr8
https://media.giphy.com/media/xTk9ZA3bn9DOf9ODKw/giphy.gif

Students might be interested to know that, on average, actresses are younger than actors. A nice example of a distribution
Curriculum Tags: MDM4U
http://www.curiousgnu.com/imdb-age-distribution

A nice little real application of systems of equations from @bkdidact with that classic of problems about ticket sales and trying to determine how many of each were sold via these two cheque purchases.
Curriculum Tags: MPM2D, MFM2P