Is Lego Gender Biased?

Here was how our conversation in math class (MFM1P) went…..How many pieces make up this Star wars Lego ship? Screen Shot 2015-02-23 at 3.28.54 PMWe started with that picture and had a great conversation around Lego.

Then I showed this one.

Does the pool/hot tub have more pieces/less pieces/ or the same? This turned into “boy” Lego vs. “girl” Lego. My personal opinion is its all great…. My 3 daughters are just as excited to play with Yoda as they are with Disney princesses. Girls in the class agreed that they didn’t need their own line of lego!!!

I moved our conversation a little forward with asking Which costs more? And which should cost more?

Screen Shot 2015-02-24 at 5.46.05 AMAnswers:

Anna — Friends should cost more because it’s a newer brand.

Joe — Star Wars costs more because it’s a popular brand.

Jacob — The friends cost more because there are more pieces.

Kristen — Friends should cost more because the pieces aren’t standard.

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How does Lego price it’s kits? Jacob suggested that its by number of pieces and the class agreed that has something to do with it. I Let them struggle here and see if they can discover the price per piece.

Some students found number of pieces per dollar and some found price per piece.

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We all came to the same conclusion. We discover that Lego friends has the lower price per piece($0.08 compared to $0.11). Is this always true?

Let’s see! We go through a number of different Star Wars Lego sets finding the unit rates.
We notice that they are not all the same so we find the average rate.

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 Get the whole slide show

We then go through Disney and Lego Friends sets and calculate the rates.

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Tracking Sheet

We saw that on average the Friends and Disney sets were $0.16 /piece compared to Star Wars’ $0.13/piece. Minds Blown!! We also graphed each on the same axis.

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We then used our work to determine what each of these sets will cost?

Screen Shot 2015-02-24 at 6.12.56 AMThe class conclusion: Lego sets are pricing their Lego Friends and Disney sets higher than Star Wars sets! Girl vs. Boy conversations came back up and I threw this set out at them……and they were outraged by the price!!!!!


IMG_3035 I should let you know in my small class of 15 students……12 of them are girls!!!


Get the whole slide show (PDF) or Keynote

Get the Desmos page

Update –Add ons — From Matt “Lego Activist” Vaudrey

The Power of Match My Graph

I was checking out twitter last week and ran into this from Dan Meyer:

and I had a concept coming up that I have always had a tough reaction to. I threw it out there.

To get students to be interested in it I wanted them to be “dying” to figure it out.

I thought about putting them in a place where they had to struggle— I wanted to open up the middle!
Michael Fenton has a series of Match my Parabola challenges and I thought of those. I modified his challenges a bit to include those examples from my tweet.

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Click to access Desmos page


The idea here was that they would be able to write most of the factored form equation since they were given the zeros, but have to figure out the “a” value that creates the matching equation.


Struggling to fit an equation


There was a lot of trial and error….most groups, by trying different values got an “a” value very close. This allowed us to ask: How accurate are we? and is there a better way? They were hooked. They were ready to try a new method.

We discussed how knowing a point on the graph helps and how we can use the equation and the point to find the exact value of “a”. The best part is the self checking in Desmos! They can put the equation in and magically see it match!

They moved on to challenge 2 with this new method and felt a ton of success getting the correct equation with minimal struggle.
When we encountered the third they started right away which amazed me. I thought they would shutter at the exact value zeros….but no!

Exact roots

Exact roots

They went right into the same strategy….each group struggled a different steps depending on their comfort level multiplying radicals. We worked through it and came up with a “nice” a-value…..and Desmos confirmed our correct answer.

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The magic really happened when I suggested that we re-work the “ugly” equation with the roots and see if we can determine a nicer one. After simplifying and putting the “nice” equation in Desmos to see they were the same equation I heard “Wow, that is awesome” and “cool”. Great things to hear after a lesson.Screen Shot 2015-02-24 at 8.50.09 AM

Creating that initial struggle is so powerful. I think we underestimate this. If you haven’t tried Michael’s Match my Parabola …..go give it a try! Awesome stuff!

Knot Again!

I am loving Alex Overwijk’s Knot activity more and more.
Go ahead and read about it!

Ropes of Different Thickness & Equal Lengths

I’m a huge advocate for having kids get their hands dirty and try things out. This one is particularly awesome because students get to experience how the rope length changes. They get to feel and create that change.

For those of you who don’t have ropes….or use this after the activity as part of a consolidation.
Problem 1- Solving a linear equation.
Act 1

Knot Again! Act 1 from jon orr on Vimeo.

Act 2
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Act 3

Knot Again! from jon orr on Vimeo.

Access all files

Problem 2 – Solving the system
Coming soon.

Super Mario – Super Pear Deck

One of my favourite 3 act math tasks is Super Mario from Nora Oswald. I’ll be teaching it a few times this semester and here is our plan….

Act 1: Show the video…

Instead of showing right to the end we are going to pause it right here….

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At this point we’ll generate questions, wonder things while being curious.  If we pause here some will want to know where he lands….then we should wonder how many points he’ll get. So let’s tackle those… first estimating. Cue…PearDeck!

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You’re right, it’s blurry.


Students use the draggable point to place where they think Mario will land. Have a discussion on parabolas/quadratics (other lesson).

Play the rest of the video……and then show this slide on PearDeck.

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Not only do we want students to guess how many points Mario should get……let’s get them to fill in the point distribution. Should it go up “evenly” or “rapidly”. Fill in the points along the scale.

Screen Shot 2015-02-09 at 9.36.48 PM Act 2:

Develop the idea that the points depends on the height of the pole. Students should ask for the distances…….have them measure. Hand out this to use with rulers

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They then use the Desmos file to test out different models. Have them go through fitting curves for linear, quadratic, and exponential models. After fitting THEIR best curves, have them use the regression built into Desmos.


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Click here to go to this desmos page

They should develop an estimate for the points for each model…..then make a decision on what Nintendo did. Back to PearDeck:

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Use the draggable dot to have students pick…..discuss the idea that Nintendo may have decided on something else altogether. Have them input their choices and NEW estimates.Screen Shot 2015-02-09 at 9.06.56 PM


Finally let’s reveal the answer…..what did Nintendo really do?

Act 3: Final Answer

Thanks Nora…..great video and problem.

Next steps…..try Modelling with Clash of Clans or Penny Circle from Desmos.

PearDeck File – Super Mario

Desmos Page  – Super Mario

Spiralling grade 9 applied math

So, I’m going to spiral the grade 9 applied course! I’m a little hesitant because I’ve taught this course with a units approach for the last 10 years. But I’m also exited!!! It seems so awesome that everyday we will solve problems; Alex Overwijk says

learn to uncover curriculum instead of cover curriculum

Instead of “boring up” the first day with paper and expectations, and policy, etc, etc we talked about being curious, collaborative, creative, and embracing challenge!

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So….we dove right in to this.

Act 1: Showed this:

 We took questions……and usually when I do this sort of lesson for the first time the kids are shy and not sure what to do…..most times we tell them what question we will work on and now they were being asked to come up with one. But this group took to it like water! They asked all sorts of awesome stuff like How long did it take? What picture are you making? What does this have to do with math? (my favourite) What are the dimensions? How many stickies did it take?

All awesome ones…..and we picked how many stickies to start and took guesses!

Act 2: Here is what they wanted to know so we could find how many stickies.

I am always blown away by the solutions students come up with…..I have one in my “math teachery” mind ….here are two:

This is the solution I expected…Find the area of each then divide the board area up by the sticky area… the number to fill….609!


Here is one I didn’t expect: Kids divided the board width by the sticky width….. = number of stickies that would go along the width. Did the same for the length…..which gives them the dimensions of the board in terms of stickies 21 by 29… the number of stickies is the area of the board!

IMG_1064This was awesome to see! Great intro to discussing area models…and using non-standard units to measure sides.

Act 3 – We revealed how many

Sequel: To extend this I turned the problem around!

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This is our lead in to discussing optimization! What would be the smallest perimeter we could make? etc!! Also, next time I want to open it more and not limit the “boards” to be rectangles. What other shapes could we make with 1350 stickies?

More spiralling happening next day…..Doing Corner to Corner and Pythagorean Theorem. Here is a Google Sheet that has a rough outline of activities I’m doing in the spiral. Any tips/feedback out there????

Ready for round 2?

Second semester is starting tomorrow and I just wanted to get down my ideas on things I will be changing and things I will be keeping…..

New things…

I’ll be using the spreadsheet I modified from @alicekeeler. Although I plan on using Kyle Pearce’s further modified version.

I have slightly modified old my assessment approach (again). I’ll share later.

Kyle and I have been Tweeting back and forth all weekend about spiralling our grade 9 applied classes. We have been teaching using an inquiry based approach (4 part math lesson) and thought that spiralling would fit right in. We’ll keep you posted. Here is my day-to-day plan by topic and task, so far .

I’ll Continue….

a ton of stuff….but here are a few

Keeping my students curious.

Strengthening the connection between algebraic representations and graphical representations using Desmos! 

Documenting my class by taking a picture/tweet for every school day.

Warm ups – To start every class we do a warm up / starter. Most of these starters are math related but for me the most important part is that the starters allow our class to “Gel”. My buddy @Regan_bio is an advocate for always saying we should show our students that we are human and remember they are human too. Take the first 5 minutes of class and be a good human with your kids…..maybe they will be more ready to do some math!

Recently Mary Bourassa has shared her great list of daily warm ups for her grade 10 applied class. Check out her warm ups.

Here’s what we have been doing…

Monday’sEstimation180 – As a class we complete one of these great challenges (10 minutes). We track our progress on Andrew’s / Michael Fenton’s provided handout.

Tuesday’s – Visual Patterns. I choose a pattern for us to determine the equation.

Wednesday’s – Pictionary – Our class is split into two teams. They take turns drawing and guessing objects, sayings, math ideas that I have picked out. Most of the time this is a non math game. (10 minutes)

Thursday’s – Throw Back Thursday — I choose a question / skill that my class has been exposed to in the past and we work on our whiteboards on this as a review question.

Friday’s – 20 Questions. — I pick something and the class has 20 yes or no questions to try and guess what I have picked. We then play a second round where the class together picks something and I try to guess. (10 minutes).

Have an exciting second semester everybody!