Math Links for Week Ending Apr. 13th, 2018

We've all see Desmos art before. They share loads of it on their website. But today I saw the craziest Desmos drawing today. Over 7000 lines of formulas by @SumDumThum needed to create this picture. When you open the link up, be patient. It takes the Internet a few minutes to catch up to all the code on this but it is pretty cool once it comes up.
Curriculum Tags: All
https://www.desmos.com/calculator/vn9imd74ne

I love when teachers use the long game. In this case @saravdwerf does it by hanging three balls from her ceiling at the beginning of the year that she wouldn't use until now. Some kids don't notice them others ask what they are for. She just says "you'll see". Then she uses them to connect to 3-D graphing and solving three variable systems of equations. That short description doesn't do it justice so look at the full post to get the 411.
Curriculum Tags: MCV4U
https://saravanderwerf.com/2018/04/08/why-i-hang-orange-plastic-golf-balls-from-the-ceiling-of-my-classroom-a-favorite-teaching-moment/




We put out a few Desmos activities this week. This one is a short intro to calculus topics like the connection of the slope of the secant to the slope of the tangent as well as the idea that if you zoom into a curve enough, you can approximate that curve with a straight line. It was based on some work originally done by @MathGeek76
Curriculum Tags: MCV4U
http://engaging-math.blogspot.ca/p/desmos-activities_10.html


The other ones are some EQAO practice activities for geometry I am trying out. The idea is that students can practice old EQAO geometry questions using the sketch feature and then measure their angles directly using the Desmos geometry.
Curriculum Tags: MPM1D, MFM1P
http://engaging-math.blogspot.ca/p/desmos-activities_10.html








We also put together a new dynamic web sketch this week on the beginnings of rotations. Here students can investigate rotation of a hexagon and irregular shape about their centres and off centre (in multiples of 90 degrees). Then they have two pages of challenges where there are randomly generated shapes where students get to try to work out the correct rotation. It was really meant for grade 6 students but could be used as review for grade 7 students.
Curriculum Tags: Gr7G
http://engaging-math.blogspot.ca/p/web-sketches.html

Doing tiling of the plane with your students? Then this cool Desmos sketch from @Von_oy is something you might want to try.
Curriculum Tags: Gr7G
https://twitter.com/von_Oy/status/983048095217930240

new and improved hexagon tiling on @Desmos (with rotating tiles!)https://t.co/afDr2bfheC#mtbos #iteachmath @madewithDesmos pic.twitter.com/LYWHF9LzGw

— Suzanne von Oy (@von_Oy) April 8, 2018

We've been using a lot of the Mathies.ca apps lately and they are continually improving them and adding features. This week the Colour Tiles app got the Save/Load feature. So now you can create some initial states that you can share with your students so that they don't have to start from scratch.

Curriculum Tags: All
http://mathclips.wikispaces.com/Colour+Tiles

It's conference season and @MrOrr_Geek has you covered with four tips to get the most out of your conference experience. My favourite is #4 - One New Thing. That is, take one thing that you learned at the conference and implement it when you get back. Don't sit on all that new knowledge, make it work for you. Read the rest of his tips at the link below.

Curriculum Tags: All

https://mrorr-isageek.com/how-to-get-the-most-out-of-the-conferences-you-attend/

We have added to our collection of videos on conceptually looking at operations with fractions. This long(ish) video goes through a progression that would help students develop the fraction division algorithm. This video is intended for teachers to see how that progression could go.
Curriculum Tags: Gr8NS
https://www.youtube.com/watch?v=PxZx54nfrWg

We also added to our activity on visual patterns by creating this video that shows how you might use the cards to develop a progression where students can get the equation of the algebraic expression for a linear pattern.
Curriculum Tags: Gr7PA, Gr8PA
http://engaging-math.blogspot.ca/2017/12/visual-pattern-cards.html

When you first look at this "math trick" posted by @DonFraser9, you might just dismiss it (especially if you don't care for math tricks). But there is a lot of good number sense and problem solving that you can have your kids go through to figure out why it works. My favourite way to use it would be to come up with the algebraic expression that models why it works.
Curriculum Tags: Gr7PA, Gr8PA, MPM1D, MFM1P
https://twitter.com/DonFraser9/status/984450688867446785

Worthwhile?? #MTBoS @Bedford_Mrs @MatthewOldridge @AllenMath @FSlimati @cherandpete @Mathgarden @MathletePearce @mraspinall @paul_math @fawnpnguyen @kspry @CathyMarksKrpan @CathyMarksKrpan @MathCoachCorner @davidpetro314 @MrOrr_geek @MrSoclassroom pic.twitter.com/REiVc2xlJh

— Don Fraser (@DonFraser9) April 12, 2018

When I first looked at this image from @MSBJacobs asking if these were similar, I thought, yes, but I was quickly reminded in the comments that only triangles are similar if all their angles are equal. It's a great exercise for student when exploring the concept of similarity.
Curriculum Tags: Gr7G
https://twitter.com/msbjacobs/status/984445127191035906

Are these trapezoids/trapesiums similar? #iteachmath pic.twitter.com/vKMxmbsqUy

— Michael Jacobs (@msbjacobs) April 12, 2018