Math Links for Week Ending Feb. 14th, 2014

It's Valentine's Day today so why not have a post with carderoids in them. Thanks Desmos.

Curriculum Tags: All

https://www.desmos.com/calculator/4dqgvrtdze

Trig identities a can be and issue as their abstractness can be a hurdle for many kids. Don't get me wrong, I think it's important for our kids to be able to work in abstractions but if there are ways to make topics less abstract than they need to be, then I think that's a good thing. That is why I like this post about a graphical way to get to the Pythagorean trig identities. Well done.
Curriculum Tags: MCR3U
http://samjshah.com/2014/02/10/trigonometric-pythagorean-identities/

I love learning stuff about things I like. For example, to day I learned you can import pictures into Desmos from Mary at the M^3 blog. I love doing this with Geometer's Sketchpad (my premade sketch is here) but now that I know Desmos does it that gives a nice alternative. Although I do like my sketch because it has a feature to scale the axes so that the equation actually has a connection to real measurements. So take a look at this blog post and if you want some more images to use, you can look at some I have collected here.
Curriculum Tags: MFM2P, MPM2D, MCR3U, MCF3M, MBF3C
http://marybourassa.blogspot.ca/2014/02/mfm2p-day-6.html

There is nothing like a real contextual problem to expose the problem people have with probability (a lot of "prob's" in that sentance). Here is the context. You are taking a medical test that is 95% accurate when people have the disease (in this case cancer). So this means there are 5% false positives. If your results come back positive, should you be concerned? The counter intuitive result is "no". John Allen Paolos wrote about this 4 years ago (and just retweeted it now) in the context of mammograms. So here's the scenario: 95% accurate when people have cancer, 99% accurate when people don't have cancer and assume that 0.5% of the 100,000 person population actually have cancer. I will leave it up to you to do the math or you can just click on the link below.
Curriculum Tags: MDM4U
http://www.nytimes.com/2009/12/13/magazine/13Fob-wwln-t.html?_r=3&emc=tnt&tntemail1=y&

I think one of the best things you can do for students is not give them the answers. To take Dan Meyer's tag line "less helpful". I realize that this is totally counter intuitive to teachers. Most of us got into teaching because we like telling people how to do stuff. So when a kid asks a question (or gives an answer that is wrong), it is a natural reaction to just give them the answer (or just say 'nope'). But why not, instead, lead them to the answer or at least have them reveal their thinking (even when they are correct). That is why I like this post from Andrew Stadel so much. It gives tips on how to approach those situations in ways that will best benefit the student.
Curriculum Tags: All
http://mr-stadel.blogspot.ca/2014/02/explain-that-please.html

For any of you teaching conversion from metric to imperial (and vise versa), this video from Matt Parker gives a nice overview of the logic behind the imperial system.
Curriculum Tags: MFM2P, MBF3C, MAP4C
https://www.youtube.com/watch?v=r7x-RGfd0Yk

Math Links for Week Ending Nov. 16th, 2013

Need some data? Who doesn't Numbeo is a site where you can get all manor of data sets. Cost of living, Crime, Price Indexes, Pollution and much more. Do you want to get real data for your classes? Then this is a great place to look. Thanks to Mike Lieff for this one
Curriculum Tags: MBF3C, MDM4U, MAP4C
http://www.numbeo.com/common/

I have recently heard a great distinction between adults who know how to do math and math teachers. To be a math teacher, you not only need to know math but you also have to be very good at deciphering the mistakes found in student work. Otherwise how else could we help them get better. "This site is about compiling, analyzing and discussing the mathematical errors that students make. Every day a new mistake is posted." Got an example you want to submit? Go ahead. And join the conversation.
Curriculum Tags: All
http://mathmistakes.org/

You have probably heard of the game Headbandz. If not, the premiss you wear a head band with a card on it that has an image or a word and your partner has to somehow get you to say what is on your head without saying the actual word. Well, how about doing that for properties of quadratics? Check out this blog post to see how. Thanks to Dan Meyer for pointing out this one.
Curriculum Tags: MFM2D, MBF3C
http://marybourassa.blogspot.ca/2013/10/quadratic-headbanz.html






I was reminded of Census at School recently when talking to a teacher about grade 7 math. The Census at School program is an educational branch of Statistics Canada and its a great way to get a boat load of data from your students. You start by creating an account and setting your class up. Then you give your students the class code and they fill out a survey online (takes about 20 min) which has demographic questions, measurement questions (height, foot size etc), interest questions, school questions, tests for reaction time and logic etc). Then you can download the Excel file with all the data. The rest is up to you to create graphs of all type using their data. One of the other features is there are data sets that you can download of students from all over the world.

Curriculum Tags: Gr7, Gr8, MBF3C, MDM4U, MAP4C
http://www.censusatschool.ca/

More data can be found from Scholastic's Kids USA survey. Data results from topics like families, censorship, sports, school uniforms and more. Thanks to Jody Barron for this one.
Curriculum Tags: Gr7, Gr8
http://teacher.scholastic.com/kidusasu/

Are we born with number sense? A new study tries to study number sense in infants and how it relates to number sense when older. How do they do that? Its actually pretty neat. I am not convinced of how valid it is but it is neat. Check out the video in the link below. None the less, they seem to see that there is a correlation between an infants numeracy skills and their skills three years later.
Curriculum Tags: All
http://phenomena.nationalgeographic.com/2013/10/22/math-for-babies/

This is an awesome minds on for grade 8 math when talking about surface area and volume of a sphere. Could probably be used as a review in grade 9 applied math.
Curriculum Tags: Gr8, MPM1P
https://www.youtube.com/watch?v=jmpvGxa2iYI

Math Links for Week Ending Sept. 13th, 2013

I am not sure how long this has been around but it seems to be a repository for all of the in house created sketches for GSP. Very inviting site and these sketches really exploit the power of Geometer's Sketchpad. There is stuff for all grade levels and even an indicator for those sketches that are iPad friendly.
Curriculum Tags: All
http://www.dynamicnumber.org/

Despite the title of this TEDx talk (Why Math Instruction is Unnecessary) I like how John Bennett takes us on his journey of discovery that much of the math that we teach is basically just a construct of our curriculum and not really necessary for everyday life. But the real focus of his message is that problem solving and critical thinking are.
Curriculum Tags: All
http://www.youtube.com/watch?v=xyowJZxrtbg

Many have long said that mathematics was the way to a high paying job. Well now I guess we have the data to prove it. The US Census has always asked about income and level of schooling but in their most recent surveys they have also asked what people's majors were. The Planet Money people have a great podcast on the results (long and short versions below). And the survey says: Applied math (engineering, computer science etc) seems top the list. What's at the bottom? Psychology. A couple of things that resonated with me about this were a) that, in general, it didn't matter where you got your degree and b) it really had more to do with supply and demand. If you want the actual pdf of the full study click here.
Curriculum Tags: All
Long version http://www.npr.org/blogs/money/2013/09/11/221417806/episode-485-whats-your-major
Short version http://www.npr.org/blogs/money/2013/09/10/219372252/the-most-and-least-lucrative-college-majors-in-1-graph

I am way behind on the I Speak Math blog posts but this one about how now there are more #mathchat had a Twitter chat about the math topic of the day. Now there are these more specific chats that go on. From middle school math all the way to calculus and statistics. Take a look here for your favourite topic.
specific "chats" about math on Twitter now. For a while every Monday and Friday (I think)
Curriculum Tags: All
http://ispeakmath.org/2013/09/02/weekly-math-subject-chats-are-live-now/

Another great TED talk about visualizing data. Chris Jordan is an artist who creates social commentary art that is often more than it seems (when you look closely at it). For example an image of the Titanic made of 67000 images of mushroom clouds (equal to the number of metric tons of uranium/plutonium being stored temporarily around the US). Check out his website (http://www.chrisjordan.com/) to be able to zoom into his works (there are a lot of them). Here is a perfect way to mix social justice and data management.
Curriculum Tags: MDM4U
http://www.ted.com/talks/chris_jordan_pictures_some_shocking_stats.html

"Would you rather...." is a blog that specializes in posing questions that asks the reader to make a choice of two similar situations and use math to justify that choice. There are a lot of different math topics that could be used here but it seems many fit into the Number Sense strand (I could be wrong here as I just skimmed the site). None the less these are great starting points for math conversations.
Curriculum Tags: Gr7, Gr8, MFM1P, MPM1D
http://wyrmath.wordpress.com/

These math "mysteries" are all really attainable for many students to understand (ie they can easily mechanically verify them) but they are some of the most famous unproven theorems. A neat way for students to see how proving something definitely can be very difficult. Included are the Goldbach Conjecture, Perfect Numbers and Mersenne Primes (plus people have suggested others)
Curriclum Tags: All
http://plus.maths.org/content/maths-minute-number-mysteries



I like this App to visualize Factoring from NCTM's Illuminations. Too bad it doesn't work on an iPad but its a nice visualization
Curriculum Tags: Gr7, Gr8
http://illuminations.nctm.org/ActivityDetail.aspx?ID=64

Here is a great way to introduce FOIL in secondary and in elementary I like the suggestion made by @emergentmath "Here's your lesson plan tomorrow: Stop the video after 1:30 and ask "why does this work?""
Curriculum Tags: Gr7, Gr8, MPM1D, MFM2P
http://www.youtube.com/watch?v=PYrgjMubh-c

I don't think you will ever need to describe how a Venn diagram works if you just show this example. There are more on the main site (http://stephenwildish.co.uk/) though not all dealing with data.
Curriculum Tags: MDM4U
http://stephenwildish.co.uk/images/holy.jpg

Redbull sponsored a contest to take the image of extreme thrill seekers in action. Some cool pix but this one fits quite well with modelling quadratics. Just import this into GSP or Geogebra and model the strobed snow boarder with a quadratic. Note that it may look kind of flattened out but that has to do with the fact that the snow boarder is rotating in flight. But it's the centre of mass that follows a parabolic arc.
Curriculum Tags: MPM2D, MFM2P, MBF3C, MCF3M, MCR3U
http://www.wired.com/rawfile/2013/09/red-bull/#slideid-39351

Math Links for Week Ending Sept. 6th, 2013

I really like this example from the Mathalicious blog (even though they make a spelling mistake in the title - though @mathtans suggests this is on purpose prisn = prison). I saw this graphic earlier in the week when the blogsophere was making fun of it but Mathalicious has found a way to make it relevant to the math classroom. It deals with the idea of false positives in large samples. I have always gravitated to these examples as they really accentuate the problems with any sort of testing where the results are based on a probability or percentage.
Curriculum Tags: MDM4U
http://www.mathalicious.com/2013/09/prisn/



I have been starting to create some simple Geometer's Sketchpad files that could be used as a Minds On or intro to lessons. This one is a simple sketch that allows students to visualize a guess of how big a percentage is. They can check their answer, get a hint and then reset the question so it randomly changes the situation. It was designed to use the iPad version of GSP, Sketch Explorer. Try it out
Curriculum Tags: Gr7, Gr8, MPM1D, MFM1P, MAT1L
http://sketchexchange.keypress.com/sketch/view/823/percent-guesser

Here is a nice application of percent that is very real world. Dealing with percents of percents when talking about resource use on an Android phone.
Curriculum Tags: Gr7, Gr8, MPM1D, MFM1P, MAT1L
http://www.androidcentral.com/new-google-services-uses-more-battery-old-and-google-needs-fix-battery-screen-already


I like this activity because its hands on and its about sampling. Specifically dealing with the idea of the effects of sample size. Thanks to Dan Meyer for this one.
Curriculum Tags: MDM4U
http://17goldenfish.com/2013/04/23/first-past-the-post-and-the-dreaded-disease-z/





Here is a nice real world optimization problem that deals with perimeter, area and money. Basically, how much money would you save to try to build this playpen on your own. Thanks to Dan Meyer for this one too.
Curriculum Tags: Gr7, Gr8, MPM1D, MFM1P
http://mtsmc.blogspot.ca/2013/04/patio-math-toddler-edition.html






I don't want to spread negativity but this blog post about a Khan Academy video seems right on. It kind of exemplifies how the Khan videos are not really stelar in terms of the teaching (in this case having out right mistakes). They serve a purpose but they shouldn't be your go to resource. But that is not really why I like this post. I liked it because it uses something I hadn't heard of before (or at least didn't know the name of before). Using a two-way table instead of a Venn diagram. I agree that this seems to be way more informative than the Venn diagram. Check it out.
Curriculum Tags: MDM4U
http://learnandteachstatistics.wordpress.com/2013/09/02/khan-academy-probability/


There has been a lot of blog posts about analyzing Double Stuffed Oreo's to see if they are actually double stuffed. Here is a tweak dealing with systems of equations.
Curriculum Tags: MPM2D, MFM2P
http://christopherdanielson.wordpress.com/2013/09/04/college-algebra-with-christopher/


Yummy Math has a nice activity that uses an infographic from visual.ly about the amount of caffeine in various coffees. As it is with all Yummy Math activities there is a worksheet but if you want the solutions and an editable version of the worksheet.
Curriculum Tags: Gr7, Gr8
http://www.yummymath.com/2013/how-much-caffeine/

I think that these four suggestions are good though more relevant as kids are younger. I certainly agree that speaking well of math is the first step. We have an uphill battle in the math arena since most people have an easy time dissing math and of course that filters down to kids and then we get them as students. But I like the suggestion to play games. Using dice, cards, and problems solving skills on a regular basis is going to help kids in math class. Check out the other tips here.
Curriculum Tags: All
http://www.edudemic.com/2013/08/four-tips-parents-encourage-math-skills-home/

I think this building was designed by Dr. Heinz Doofenshmirtz. An application of parabolic focussing.
Curriculum links: MFM2P, MPM2D, MCR3U, MCF3M, MBF3C
http://io9.com/new-skyscraper-unexpectedly-generates-a-solar-beam-that-1263670017

Here is a scientific and topical example of periodic phenomenon. The reversing of the Sun's magnetic field. Could possibly be modelled with a sinusoidal function with a period of 11 years. Thanks to Joe Goulet for this one.
Curriculum Tags: MCR3U
http://blogs.smithsonianmag.com/science/2013/09/the-suns-magnetic-field-is-about-to-reverse/

Math LInks for Week Ending Aug. 30, 2013

Data from Twitter has given empirical data to measure the subtle differences between a nerd and a
geek. 2.6 million tweets from Dec 2012 were analyzed to find terms associated with geek and nerd and a cool graph was born.
http://slackprop.wordpress.com/2013/06/03/on-geek-versus-nerd/
Curriculum Tags: MDM4U

From Kyle Pearce we have a new addition to the 3Act Task cannon. This time dealing with linear relations, proportional reasoning and mowing the lawn.
http://tapintoteenminds.com/2013/08/24/mowing-the-lawn-three-act-math-task/
Curriculum Tags: MPM1D, MFM1P

Everyone that teaches quadratics will eventually use a "frame" problem. Here is a nice rework of an already good activity dealing with this type of problem from the I Speak Math blog
http://ispeakmath.org/2013/05/02/quadratic-frames-totally-nguyening/
Curriculum Tags: MPM2D, MFM2P

Is algebra needed? Some words from a novelist telling us why we don't need it. Do you agree?
http://www.popsci.com/science/article/2013-08/argument-against-algebra
Curriculum Tags: All

New from Vi Hart. Doodling in Math class returns. This time the dragon curve fractal
http://www.youtube.com/watch?v=EdyociU35u8
Curriculum Tags: all

Everyone needs a calculus cartoon
Curriculum Tags\: MCV4U
http://www.smbc-comics.com/?id=3087