Math Links for Week Ending Nov. 14th, 2014

I am a big fan of collecting real data in math class and if you can do that and have fun at the same time then even better. Mr. Orr noticed this great video on Jimmy Fallon and quickly noted the connection to scatter plots. I realize that it is no longer pumpkin season but he has created a Google form so you can add your own data and then summarized it on a Desmos Graph. All harnessing the power of Twitter to make the activity better. Thanks to Kyle Pearce for this one.
Curriculum Tags: MPM1D, MFM1P, MDM4U, MAP4C
http://mrorr-isageek.com/?p=3397

I just added a new Geometer's Sketchpad sketch to our Engaging Math blog. This is a fun one that has students guessing the size of a percent by sliding a point to create the shaded area. It was designed for the iPad (using the Sketchpad Explorer) but of course works in the desktop version of GSP as well. Download the sketch at the link below.
Curriculum Tags: Gr7, Gr8, MPM1D, MFM1P
http://engaging-math.blogspot.ca/2014/11/geometers-sketchpad-percent-guesser.html

Here is another new one from our blog Engaging Math. It's another one that can be used to create groups. In this case, groups of three in grade 9 academic or grade 10 applied. Students are each given a card that has either a table, equation or graph of a linear function and they are asked to find the other two people with the same relationship.
Curriculum Tags: MPM1D, MFM2P
http://engaging-math.blogspot.ca/2014/10/sort-students-into-groups-using-linear.html

This video was part of Mathalicious' Kickstarter campaign. When you watch it, it seems like a great connection to area of a circle and unit rate. Perfect for grade 8. But on the Mathalicious blog they have repurposed it to look at modelling the relationship between the pizza and the proportion of the crust. They have done it dynamically with some interactive applets and modelled the function. This would be great for modelling in Advanced functions. But you could also make connections to quadratics as well so you might be able to fit it in in grade 10 or 11 too.
Curriculum Tags: Gr8, MPM2P, MFM2D, MCR3U, MCF3M, MBF3C, MHF4U
http://blog.mathalicious.com/2014/11/02/pizza-pi/

The Sign of the Times blog have had a bunch of new interactives based on GSP sketches. And the good thing for some is that you don't need to have GSP to run them. They are puzzle based and could be used. The first is one that is a guessing game gives clues about a number between 1 & 25 by stating whether it is a multiple of any digit from 2-12. This is good for any time you just want to practice factors
Curriculum Tags: Gr7, Gr8
http://blog.keycurriculum.com/reasoning-with-multiples-to-find-the-mystery-number/

This one is not clear right away but there are 10 unknowns. Drag the circle over any number of them and it will show the sum of those unknowns. Your job is to determine what the unknowns are. And to make it more difficult, the numbers are moving. I see this as a great introduction to systems of equations in grade 10.
Curriculum Tags: MPM2D, MFM2P
http://blog.keycurriculum.com/dancing-unknowns-you-havent-seen-simultaneous-equations-like-these/

The third one is a neat little puzzle that requires students to create an isosceles triangle with the only stipulation that one of the vertices must be in a random location.
Curriculum Tags: Gr7
http://blog.keycurriculum.com/isosceles-triangle-puzzles/

Another nice one from Kyle at Tap Into Teen Minds. This time a student video on solving proportions. I like the visual way that he went about doing this and that he didn't jump right to the balance method.
Curriculum Tags: Gr8, MPM1D, MFM1P
http://tapintoteenminds.com/2014/10/17/visualizing-proportional-reasoning-working-ratios-proportions/

Do you want to mess with your kids. How about proving that all triangles are equilateral. It might fit into grade 7 since they talk about triangles there but really maybe anywhere. Thanks to Mike Lawler for this one.
Curriculum Tags: Gr7
http://mikesmathpage.wordpress.com/2014/11/06/using-numberphiles-all-triangles-are-equilateral-to-talk-about-constructions/

A proof without words of the cosine law. Follow the link for more details
Curriculum Tags: MPM2D, MFM2P
http://www.cut-the-knot.org/pythagoras/CosineLawMolokach.shtml

So fun. Fractal Silverware
Curriculum Tags: All

http://boingboing.net/2012/10/01/fractal-cutlery-that-fringes-o.html