Friday, April 11, 2014

Math Links for Week Ending April 11th, 2014

I have been showing this example from Deborah Ball for about a year now. I really like how she really articulates what distinguishes a good math teacher from someone who just knows how to do math. The neat thing is she does it in front of the Michigan legislature. For a longer talk by Dr. Ball on this topic you can click here.
Curriculum Tags: All

I am fascinated by this Veronoi Diagram. Each dot represents an airport and the regions represent areas that are closest to that airport (compared to another airport). So the lines separating the regions represent places that are equidistant to the nearest airports. Its a really neat geometric property that could be adapted to the geometry units in grade 7&8 connecting to quadrilaterals. On the site the diagram is an interactive so that the entire globe's airports are mapped out. Thanks to @ddmeyer for this one.
Curriculum Tags: Gr7, Gr8

I like it when concepts can be introduced in unique ways. Here Mathy Cathy does has an interesting way to introduce compound events in probability. A simple true and false test (with random answers). Kind of reminds me a bit of the March Madness contest but on a smaller scale.
Curriculum Tags: MBF3C, MDM4U

I like Kyle's Baby Beats 3 Acts task. Proportional reasoning is a topic that needs as many varying tasks to help students get a handle on it.
Curriculum Tags: MPM1D, MFM1P

We have seen cell phone plan questions before. And they all have a little bit of the pseudo math thing going on. But this one takes a slightly different take. Instead the standard fixed monthly cost and then a per minute charge (which is typically not how a phone plan works anymore) it has the fixed cost and then the extra cost for more data. A little more realistic.
Curriculum Tags: MPM1D, MFM1P, MFM2P

I am a sucker for raw data. On this site not only is there neat visualizations but they have all kinds of raw data. Check out this set on over 40,000 meteorites. Enjoy.
Curriculum Tags: MDM4U

Speaking of data, who doesn't like sports data. This post does a great job of summarizing places you and your students can get sports data. Thanks to Free Technology for Teachers for this one.
Curriculum Tags: MBF3C, MDM4U, MAP4C

Another one from Free Technology for Teachers is about four sites for free graph paper (of many types): Imcompetech, Print Free Graph Paper, Math Drills, Gridzzly. Some other graph paper sites include Printable Paper, Math Worksheet, Dynamic Paper, Free Online Graph Paper, & Math Bits.
Curriculum Tags: All

I have been known to have a bit of heavy foot while driving. So it's ironic that I have been saying that speeding doesn't get you there much faster (in general). I even wrote a task about it about 10 years ago. You can download it here. But now you have the data to show you in what situations speeding could possibly pay off. Its a really great way to talk about rational functions.
Curriculum Tags: MCR3U

Lots of Articles this week. Here's one with our education minister talking about how we need to go back to basics. If she's on that bandwagon then I guess she doesn't get it.
Curriculum Tags: All

Not so much for intermediate and senior math but none the less the idea is still good. In terms of problem solving we don't tap into our youngest kids enough
Curriculum Tags: All

Here's an article on how women are using their training in STEM fields to create entirely new jobs
Curriculum Tags: All

This post about the statistical probability that global warming is happening (99.9%). But those deniers will then say "So there's a chance". Totally reminds me of this clip from Dumb and Dumber
Curriculum Tags: Gr7, Gr8, MBF3C, MDM4U

Who knew Cindy Crawford when to school for Chemical Engineering (I'm sure some did)? But listen to her talk about how she was on the wrong end of a stereotype from her calculus prof
Curriculum Tags: All

I was shopping with my daughter the other day and saw this sign for a sale. I like it because the implication is that it's a 60% discount but, in fact, the successive discounts work out to 52%. The math is all right on the sign but it would be a good discussion for grade 7&8 students about percents.
Curriculum Tags: Gr7, Gr8

Some common thoughts about cancer that data shows is false
  1. Unless treated, cancer is fatal
  2. The earlier you diagnose and treat it the greater the chance of being cured
The article below talks about how those two are not necessarily true. As a hint, take a look at the graph below.
Curriculum Tags: MDM4U

Some fun examples of bad math. I have seen some of these before but these two below I haven't
Curriculum Tags: All


  1. Always a good line-up of resources. While you suggest the 40% off then take an additional 20% off question from the image above would be a great discussion for 7/8 students, I might argue many high school students could benefit from the discussion as well.

    I find that students don't "really understand" percents other than the fact that 20% means multiply by 0.20. If you toss that same question into many high school classrooms at random, I bet most would assume it is 60% as you mentioned.

    Might be worth researching a bit...


    1. Really this is good for all. It's actually not a straight forward question to determine the sale price. Many students when asked to find the sale price, will determine the discount and subtract from the regular price (rather than multiplying the regular price by what remains from the discount). Doing that twice in a row (assuming they understand they are successive discounts) is a lot of potential work. So I agree with you that if you threw this to most high school students, many would struggle.

      On a related note, this is from the store Justice and when I showed a friend this image (who has girls) she recognized it right away and said "that is from Justice, I never understand their sales. Its always a surprise when I get to the checkout" I wonder if that is on purpose (that is, does Justice mean to be so confusing)