## Friday, February 19, 2016

### Math Links for Week Ending Feb. 19th, 2016

A few years ago I was a facilitator at MathCAMPPP for teachers in Barrie. It was pretty awesome. The theme for the week was fractions and I was helping to facilitate the Gr9-12 session. One of the things we discussed was how useful a number line was and used a clothesline to create it. We did some cool things with functions but I digress. The point is that I love when anyone ever uses a clothesline in math. The general idea in this activity from @MrOrr_Geek is that students get random card with a line on it to calculate the slope from. Once they calculate their slope, they place their card on the number line in its appropriate spot and what you end up with is a visual that shows how the lines look as the slope increases.
Curriculum Tags: MPM1D, MFM2P
http://mrorr-isageek.com/slope-clothesline/

I love it when teachers take it upon themselves to create a whole new genre of math problems. Not that fractions are some new invention but @NatBanting has created his new site Fraction Talks where he posts images where students have to determine what fraction of the image is shaded. Or as he describes it:
"I introduce the structure much like a number talk. I project an image, choose a section to be shaded, and ask students, “What fraction is shaded?”. Students develop an answer (and reasoning) individually, and signal to me when they are done (usually with a thumbs up). I then extend invitations to share."
The images are categorized by type so that you can have your own fraction talks in your classes. Plus you can submit your own images. Check it out.Thanks to @marybourassa for pointing this out
Curriculum Tags: Gr7, Gr8
http://www.fractiontalks.com/

We created this activity years ago and finally are just getting around to posting it. The premiss is simple, students sort cards that have algebraic equations and expressions and matching statements. There are also Explain Everything versions as well for those of you who have iPads.
Curriculum Tags: Gr7, Gr8, MPM1D, MFM1P
http://engaging-math.blogspot.ca/2016/02/number-sentences.html

It's no surprise to anyone who knows me that I am a big fan of the Five Thirty Eight site. Lately they have been posting a weekly Riddler. They are math and logic related, like this one that has it's basis in the circumference of a circle. They post the new riddler every Friday and have the solution to the previous week's on that Friday post. You have a couple of days to submit your answer (if you are into that sort of thing). But if you are looking for some brain teasers for your class, then this might be a great place to start.
Curriculum Tags: All
http://fivethirtyeight.com/?s=the+riddler

There are a lot of reasons to love Wolfram Alpha. I was reminded of one of them this week. Type in the phrase "planes above" and you get info on aircraft in the area (based on your IP address). How does that connect to math? It's a great application of trig ratios. You get the altitude, slant distance and angle of elevation. All of these can be used to verify the properties of trig ratios.
Curriculum Tags: MPM2D, MFM2P, MBF3C, MCF3M, MCR3U
http://www.wolframalpha.com/input/?i=planes+above

The first part of this video from @standupmaths is a neat application of parabolas (image, a building that lights things on fire). The rest of the video is a derivation of the definition of the parabola (including some calculus). So you might want to just stick to the first part.
Curriculum Tags: MPM2D, MFM2P, MBF3C, MCF3M, MCR3U

Here is a great Expected value question from @MathGarden. I love how he points out that a great math question doesn't need asking.
Curriculum Tags: MDM4U