Math Links for Week Ending Sept. 29th, 2017

To introduce the concept of mixed radicals, rather than just tell students, you might consider this short card sort. Students are give several cards to sort into groups that are equal in value but different in form. You can do this as a physical card sort or if you have the tech, you might use the Desmos cards sort version.
Curriculum Tags: MCR3U
http://engaging-math.blogspot.ca/2017/09/mixed-radical-card-sort.html

From the creator of visualpatterns.org, @fawnpnguyen,  comes a new site between2numbers.com. On this site you are given pairs of images and asked to compare them somehow. Proportional reasoning skills are the main idea here and eventually she expects to have enough so you could do one per week.
Curriculum Tags: Gr7, Gr8, MPM1D, MFM1P, MAT1L, MAT2L
http://fawnnguyen.com/between-2-numbers/

I like simple activities and this integer bingo is a perfect example of one from @vaslona. Students are given a 4x4 bingo card (either generated or made on their own) then pingpong balls are drawn and added together to fill the card.
Curriculum Tags: Gr7, Gr8
https://logsandreflections.wordpress.com/2017/09/09/integer-bingo/

We are all bad at probability. In this article @fivethirtyeight goes over what the media often gets wrong.
Curriculum Tags: MDM4U
https://fivethirtyeight.com/features/the-media-has-a-probability-problem/

Some fun with doubling, halving and factoring from John Oliver via @ChrisHunter36. Check the post out for more details on using this in class.
Curriculum Tags: Gr7, Gr8
https://reflectionsinthewhy.wordpress.com/2017/09/11/halving-doubling-very-fun-to-play-with/



A brief history of banned numbers. Who knew?
Curriculum Tags: All
https://ed.ted.com/lessons/a-brief-history-of-banned-numbers-alessandra-king

A new one from @Jstevens009 on Would you Rather
Curriculum Tags: MCF3M, MBF3C, MCR3U
http://www.wouldyourathermath.com/would-you-rather-65/

Here's a neat little problem to practice problem solving in the context of rectangles.
Curriculum Tags: Gr7
https://fivethirtyeight.com/features/how-do-you-like-these-rectangles/

Now that's a cheat sheet and a reminder of why units are important.
Curriculum Tags: All
https://www.today.com/news/college-student-s-giant-cheat-sheet-allowed-professor-t116623

First test day of the semester and as always, I allow a 3x5 notecard. Today, a student shows up with this. Sure enough, it is 3x5... feet. As precise as I am, apparently I never specified inches and therefore yes, it was allowed. Well played and lesson learned for me. @elijahbowen_ #aacc #audacious #professorlife #accounting #winner

A post shared by Reb Beatty (@rebbeatty) on Sep 19, 2017 at 1:24pm PDT

Ok some of these are funny. Check them all out below. Thanks to @saravdwerf for this one
Curriculum tags: All
https://www.buzzfeed.com/sarahaspler/people-our-math-textbooks-warned-us-about?utm_term=.fhVOGJKGQ#.od2rWZnWP

Math Links for Week Ending Sept. 22nd, 2017

Woo hoo, I saw a draft version of this at Twitter Math Camp this year and it seems that it is finally out. Transformation golf is a great way for kids to practice rotations, translations and reflections in a nice dynamic way. I've done a bit of work in this area here and here but the Desmos stuff is so slick your kids will love it.
Curriculum Tags: Gr7, Gr8
http://blog.desmos.com/post/165555417467/free-new-desmos-activity-transformation-golf

In Ontario, we call them learning goals. Here @mathycathy calls them learning targets. Regardless of the name,  if you have your students keep track of their progress on their learning goals then you might like the way that she has co opted Desmos Activity Builder to do that. Take a look
Curriculum Tags: All
http://www.mathycathy.com/blog/2017/09/desmos-learning-target-student-reflections-inspired-by-a-tweet/




In this latest episode of @MyFaveThm they ask @JSEllenberg what his favourite theorem is and it was a neat little ditty called Fermat's Little Theorem. Which basically goes like this. Take any prime number, say 7 and raise 2 to the power of that prime, 27. Then the answer when divided by the original prime 128/7 will always have a remainder of 2. This is easily used in any class where students have to work with expressions and primes. Listen here
Curriculum Tags: Gr7, Gr8
https://kpknudson.com/my-favorite-theorem/2017/9/13/episode-4-jordan-ellenberg

I love it when teachers share their entire semester via daily posts. I think that besides this being a great exercise for teachers to self reflect, its great for other teachers to get ideas. In this case, @DaveLanovaz is giving us a day by day for his grade 9 academic math class. Check out the first post here and the rest that follow.
Curriculum Tags: MPM1D
http://sine-of-the-times.blogspot.ca/2017/09/mpm1d1-day-1.html

Here is a crazy pattern that might get your kids thinking of Pythagorean theorem and higher dimensions.
Curriculum Tags: Gr8, MPM1D, MFM1P
https://www.youtube.com/watch?v=mceaM2_zQd8

Last week I someone showed me an order of operations problem that (potentially) had two different answers depending on how it was typed into the calculator. And through the rest of the week I learned that there was an order of operation rule that I had previously been unaware of. That is when you have something like 6/2(3), even though order of operations tells us that we do multiplication and division in the order they appear left to right, the implied multiplication of 2(3) is actually has precedence. There is not a lot of info on this (and I don't know of anyone that teaches this in elementary or secondary school) but clearly it exists as you can see by some of the documentation seen in the tweets that followed my original tweet including a calculator manual page, other calculator examples and the apparent reason (that implied multiplication is treated as a scale factor and thus takes prescience).
Curriculum Tags: All
https://twitter.com/davidpetro314/status/908082923856953345

Is this some new rule I'm unaware of? Maybe @standupmaths knows if it's just this #calculator #mathchat #MTBoS #iteachmath pic.twitter.com/EAJYjFMJ78

— David Petro (@davidpetro314) September 13, 2017

Math Links for Week Ending Sept 15th, 2017

So there is a relatively new math podcast out: My Favourite Theorem is hosted by @niveknosdunk and @evelynjlamb and each episode they interview a mathematician and ask what their favourite theorem is. There is only a few episodes now but so far there is a mix of theorems well above gr12 to things that could be used in grades below gr12. Each episode is relatively short so it's a nice little podcast that you could listen to to get some neat ideas for class. For example, how about this video from 1966 about the mean value theorem. You can get all the podcasts and transcripts at this link but you can get more descriptions and extra stuff at the Roots of Unity Blog.
Curriculum Tags: All
https://blogs.scientificamerican.com/roots-of-unity/

The Theorem of the Mean Policeman (1966) from Eric Cornwell on Vimeo.

In this recent episode of 99% Invisible @mathbabedotorg talks about the problems with algorithms and other topics from her book "Weapons of Math Distruction".
 Curriculum Tags: All
http://99percentinvisible.org/episode/the-age-of-the-algorithm/

Ever see the path of satellites? Ever wonder why the path looks sinusoidal? Blame the Mercator map
Curriculum Tags: MCR3U, MHF4U
https://www.scienceabc.com/eyeopeners/why-do-satellites-orbits-look-like-a-sinusoidal-wave-on-the-world-map.html

Here's a TED-Ed video on some of the different ways to prove the Pythagorean Theorem.
Curriculum Tags: Gr8, MPM1D, MFM1P
https://www.youtube.com/watch?v=YompsDlEdtc

In this video @standupmaths does some work with i^i and makes connections to Euler's Identity.
Curriculum Tags: MCR3U, MCV4U, MHF4U
https://www.youtube.com/watch?v=9tlHQOKMHGA

This image they made with the digits of this prime is pretty cool
Curriculum Tags: All
https://www.youtube.com/watch?v=fQQ8IiTWHhg

I have always heard about Casting out Nines but never really knew what it was. It's actually pretty neat and it's a great way for your students to practice their math facts while practicing their math facts.
Curriculum Tags: Gr7, Gr8
https://www.youtube.com/watch?v=FlndIiQa20o

A painting for the artists in your class that connects to Pythagorean Theorem
Curriculum Tags: Gr8, MPM1D, MFM1P
https://www.almost-there.co.uk/unknown-pleasures-april-2016

Math Links for Week Ending Sept. 8th, 2017

When I was at Twitter Math Camp this summer one of the "My Favourites" was from @SweenWSweens. He talked about using @Desmos Marbleslides challenges all the time in his class. Well he has put all of them in one Desmos Activity. Check it out at the link below
Curriculum Tags: MPM2D, MCR3U, MCF3M, MHF4U
http://sweeneymath.blogspot.ca/2017/08/a-full-year-set-of-36-weekly.html

I think that the more real examples of how probability works we can show students the better. In this case the idea discussed is the "hundred year flood". More specifically the idea that what it means is not that once in every 100 years there will be a bad flood but instead there is a 1% chance every year that there will be a bad flood. These are two different things and they go through some of the math.
Curriculum Tags: MDM4U
https://fivethirtyeight.com/features/its-time-to-ditch-the-concept-of-100-year-floods/

"John Urschel of the Baltimore Ravens was the only player in the N.F.L. simultaneously getting a Ph.D. in math at M.I.T. But after a new study came out linking football to brain damage, he abruptly retired" - this story is probably a nice general interest topic spanning sports to math. Listen below.
Curriculum Tags: All
http://freakonomics.com/podcast/brain-damage/

Sometimes I think that when it comes to transformations, dilatations are sometimes the hardest to describe. In this series of videos Dane Ehlart has a series of videos that shows them visually. Check them out below
Curriculum Tags: Gr7, Gr8
https://whenmathhappens.com/2017/08/29/dilations/
https://whenmathhappens.com/2017/08/31/dilations-day-2/
https://whenmathhappens.com/2017/08/31/dilations-day-3/

And as an extra challenge Dane has some images where he asks to describe the dilatations then gives video solutions (see links below for solutions).
Curriculum Tags: Gr7, Gr8
https://whenmathhappens.com/2017/09/05/dilation-1/
https://whenmathhappens.com/2017/09/05/dilation-2/

Math Links for Week Ending Sept 1st. 2018

Here in Ontario the results are starting to come out for this year's provincial tests. Apparently, again, grade 6 math scores are stagnant at about half of students reaching provincial standard. Of course there are all kinds of reasons that everyone has for this but I thought that @mathewoldridge said it best in this article where he basically talks about my favourite solution, using a balanced approach of traditional and new methods.
Curriculum Tags: All
https://www.pressreader.com/canada/the-globe-and-mail-prairie-edition/20170831/281625305441609

Personally, although I get the importance of them, I have always made fun of "Think,Pair,Share" or "Talk to your elbow partner" because, really, can't you just say "Talk to the person next to you". All joking aside, I really like this tweak from @saravdwerf. She calls it Stand and Talk and she goes into great detail on how to use it to get your kids to talk about math in your classes. Well worth the read.
Curriculum Tags: All
https://saravanderwerf.com/2017/08/09/stand-talks-the-best-thing-i-ever-did-to-get-students-talking-to-one-another/

Like I said, everyone has an opinion. In this article the solution to Ontario's math woes is making sure you teach the teachers math (speaking of elementary teachers). I only partially agree. I think that, to some extent, teachers do need to know the math but more than that they need to know math for teaching. Which means needing to know how to handle things when kids make mistakes. Read the article at the link and then watch @Deborah_Ball's video about math for teaching
Curriculum Tags: All
https://beta.theglobeandmail.com/opinion/the-real-issue-in-ontarios-schools-the-teachers-need-to-be-taught-math/article36136069/

Though they don't go into too much detail about the math, it was used to determine the exact moment the space station went across the eclipse. It was only for an instant but it was so cool that they could figure it out. Math power!
Curriculum Tags: All
https://www.youtube.com/watch?v=lepQoU4oek4

I think this is really just Babylonian homework. Click the link to see the video. Thanks to @MrEsping_Math for this one
Curriculum Tags: MPM2D, MFM2P
https://www.facebook.com/NowThisFuture/videos/1708018539239319/?hc_ref=ARSA3omN7x2lj_LjZ4qG4Q3DFNKuahPLczP3-cf9qQ6obxkqSK5g2zGZeFJayxk9qNk&pnref=story

Some Logarithmic humour
Curriculum Tags: MHF4U
https://twitter.com/aap03102/status/901435497884655616

What did the Mathematician say when he was drowning....? #DoodlingOnSaturdayAfternoon #BeenWorkingWithLogsThisWeek pic.twitter.com/XgCFA89bHI

— Chris Smith (@aap03102) August 26, 2017