## Saturday, November 7, 2015

### Math Links for Week Ending Nov. 6th, 2015

I found myself looking at the Desmos Team page this week and each member has a link to their favourite graph (seriously, who doesn't have a favourite graph?) and came across this fav of @Zora_Tung. It was created by the founder and CEO of Desmos @Eluberoff so it shouldn't be surprising that it is probably one of the slickest uses of Desmos that I have seen. You enter any function and then drag points to visually show the slope of the tangent at those x values. The slickest part is when you have all the slopes at places where they are close enough to the actual slopes, the derivative actually appears (if your curious, the mechanics of that is pretty cool to - take a look when you open the graph) and if you want have a little more control then you can look at this version.
Curriculum Tags: MCV4U, MHF4U
https://www.desmos.com/calculator/a9qu2gphzj

I had a fun time Sunday morning helping out @mjfenton to tweak this activity (my daughter helped too). A nice little Desmos Activity Builder number that starts with a couple of screens from a running app and then you do some great work with proportional reasoning and direct variations. Curriculum Tags: MPM1D, MFM1P
https://teacher.desmos.com/....../5633efcb40b89698065df55a

And while we are on the Desmos band wagon we have this great fun site from @Lustomatical He used to work at Mathalicious and they use the Desmos API there as the backbone for their site. And on his site http://chrislusto.com/ he has a bunch of tutorials on how to use the Desmos API on your own site (damn, now I have something else to learn about). So here is one of the things he made. It turns any sequence of Desmos screens into an animated gif (like this one I made here). Try it out at the link below and try one on your own.
Curriculum Tags: All
http://www.gifsmos.com/

Here is a neat activity from @mrOrr_Geek that he adapted from @bobloch on angular velocity. I really love the marching in a line and spinning parts and it also reminded me of a video that I shot and posted on 101qs.com where I like asking the question "how fast are the tips of the blades moving" (spoiler alert - really fast). But back to the post. It's a nice full lesson that starts with a nice little video to set the stage and gets kids out of their seats and outside to get a real feel for angular velocity.
Curriculum Tags: MHF4U
http://mrorr-isageek.com/angular-velocity-trig-whips-elmo/
http://mathcoachblog.com/2012/10/02/experiencing-linear-and-angular-velocity/
http://www.101qs.com/1052-blowin-in-the-wind

And those problems continue to be posted on the Interwebs. That is, "the question that stumped ......" This time it is Australian students. The gist of the post is about how people were complaining about how dumb would you have to be to not get this but if you did not remember your angle properties, it would be a bit tough. It's a really nice little problem though.
Curriculum Tags: MPM1D, MFM1P
http://www.independent.co.uk/student/news/vce-further-mathematics-50-cent-question-leaves-australian-students-confused-a6719231.html

I think that dealing with disappointment as a teacher is probably a day to day thing. This post from @tina_zita reminds us that we have to turn disappointment into an opportunity to learn. It also reminds me of me of this short clip from Dylan Wiliam
Curriculum Tags: All
https://misszita.wordpress.com/2015/11/07/dealing-with-disappointment/

Last week I featured a post from @MrSoClassroom about what it means to be a teacher and this week he followed it up with a great post that is about the concept of sharing. A perfect post for the #MTBoS community who shares so much. Plus he gave me and this blog some props
Curriculum Tags: All
http://mrsoclassroom.blogspot.ca/2015/11/are-we-reluctant-to-share.html

I love this TED talk about using different perspectives in math. My favourite part is when he deals with 4/3. Thanks to @mathletepearce for this one
Curriculum Tags: All

And another one from the TEDx stage is less about Math and more about STEM but the title should get you interested "I don't do math". Which basically starts out with the concept that people are willing to say they can't do math but not that they can't read. And then goes on to explain why it is important to think scientifically.
Curriculum Tags: All

Like I said I was on the Desmos Team page and this was @ddmeyer 's favourite graph (from XKCD). Though I didn't agree with the placement of some of the fruit. I do like the concept for an interesting way to introduce the coordinate system.
Curriculum Tags: Gr7, Gr8
https://imgs.xkcd.com/comics/fuck_grapefruit.png

We see these kinds of posts all the time on Facebook and seem outrageous but just a little fact checking can show that it is not possible. The good thing is that many of the comments debunk it pretty quickly. Try to debunk it yourself (or have your students do it) and then compare with what others have said. It's a really good exercise in dealing with large numbers too.
Curriculum Tags: MDM4U