Math Links for Week Ending Jan. 26th, 2018

I have mentioned Math Is Visual before. It's creator @mathletepearce continues to try to visualize math concepts to help students understand basic concepts better. Recently he's been working on visualizing integer operations and has created this playlist that walks through basic addition and works it's way to more complex subtraction. He really takes the visual aspect seriously and you should to. But for optimal results, you really have to go through the entire playlist in order to get the benefit. Stepping in in the middle could disrupt the flow from the purely visual to the mathematical symbolic. Each video has it's own page that goes into much more detail on some of the teacher moves you might use.
Curriculum Tags: Gr7, Gr8
http://mathisvisual.com/series/integers/

I have released a couple of new Desmos Activities this week. The first deals with projectile motion. It starts with some investigation of launch angle, speed and height and then offers up some challenges. Finally it ends with a 'sandbox' for kids to play and experiment in.
Curriculum Tags: MCR3U, MCF3M, MBF3C
http://engaging-math.blogspot.ca/p/desmos-activities_10.html

The second is a pair of activities dealing with parabola transformations. The first is on translations and the second is on stretches. Along the way there are tables to complete, characteristics to describe, marbleslides to solve and a randomly generated page of equations to match with a graph.
Curriculum Tags: MPM2D, MBF3C
http://engaging-math.blogspot.ca/p/desmos-activities_10.html

It looks like @MrOrr_Geek has been working overtime to help you in your math class. In this post he explores some of the best ways you can use two truths and a lie in math class. He describes them in the video and gives you a downloadable user guide. So what are you waiting for?
Curriculum Tags: All
http://mrorr-isageek.com/4-ways-to-use-two-truths-one-lie-in-any-math-class/





Do you want your kids to work on their basic number sense but in a puzzly kind of way. Then consider having them deal with partitioning numbers (eg 4 can be 4, 3 and 1, 2 and 2, 2 and 1 and 1, or 1 & 1 & 1 & 1). Via @MathforLove
Curriculum Tags: All
http://www.thehindu.com/children/partitions-and-pieces-of-eight/article22489606.ece

Leave it to @ddmeyer to come up with a way to make the Interwebs more welcoming. A while back he started to search the Twittersphere for math teachers who Tweeted and were either new to Twitter or had no interactions. Well now he is enlisting the rest of us to do the same. He has started a new site: Lonely Math Teachers where he has scraped Twitter to find math tweets with low interaction and is asking us to interact with them. Nicely done. Check it out. 

Curriculum Tags: All

http://lonelymathteachers.com/

"Why we don't cross multiply" - that's the title of a post from @K8Nowak and what follows is a fairly thorough description as to why introducing cross multiplication too soon (or at all) is a problem developmentally for students. 

"I know that lots of people are very comfortable teaching cross multiplying, and this change is challenging."

It is uncomfortable for many teachers because that is what we learned as students. But she has some ideas as to how to pull the math off without going directly to cross multiplication. 

Curriculum Tags: All

http://function-of-time.blogspot.ca/2018/01/why-we-dont-cross-multiply.html

A very surprising result in the car crash analysis video from @numberphile. Some good math in there with working with formulas with powers as well.
Curriculum Tags: MPM1D, MFM1P
https://www.youtube.com/watch?v=i3D7XYQExt0

This is a neat little problem that deals with perfect squares.
Curriculum Tags: gr7
https://www.youtube.com/watch?v=G1m7goLCJDY

This is so fun. How do you create a 3 sided coin? Watch and find out. Along the way you'll see some geometry and some probability theory dealing with the binomial theorem and the normal distribution along the way.
Curriculum Tags: MDM4U
https://www.youtube.com/watch?v=-qqPKKOU-yY

How about some composite functions? Thanks to @mathtans for pointing this one out.
Curriculum Tags: MCR3U
https://twitter.com/giohio/status/955377264509767680

Function composition. pic.twitter.com/sI8iSo1ByR

— Steve Phelps (@giohio) January 22, 2018