First full week of classes since the week before Valentine’s day! (No joke.) We just got back from spring break and finished up our unit on quadratics with graphing and applications.

Some good stuff:

**Monday** – Desmos Polygraph!

I knew this would be a total blast, and it was. For those unfamiliar with the activity, it’s essentially a computerized “Guess Who” style partner game with a set of 16 parabolas. (Desmos has done some really smart things here, like starting off the activity with a practice round against the computer to see how the game works, and inserting questions between each round so that students can build vocabulary and get better at asking questions.) Other folks have done a great job writing up their experience leading this activity (see Dylan’s post here, which I now realize I should have reread Sunday night when I was prepping, oops) so I won’t go into details. For laughs, though, here was my favorite question asked throughout the day. Brilliant. 🙂

For homework, I asked students to read through some of the sections in their book on graphing quadratics and create a one-page “cheat sheet” synthesizing the important ideas and vocabulary. Here is one of my faves:

**Tuesday** – WODB and Graphing Quadratics foldable

For Bellwork on Tuesday, I used a “Which One Doesn’t Belong?” question from the brand new, awesome site created a couple of weeks ago by Mary Bourassa. We had done one of these style questions before, and I’ve noticed that a wide range of students are eager to offer suggestions for why each one is different – not just the students who typically speak up in class.

After the bellwork, we made a foldable to organize all of the info about graphing quadratics that students had read about the night before. I had photocopied some of the info on already to save time, and called on students in the class to help us fill in definitions and work examples as we went.

Finally, we practiced graphing quadratics by hand, from start to finish by finding opening direction, width, axis of symmetry, vertex, y-intercept, and x-intercepts.

**Wednesday** – “Make these Parabolas” and groupwork

In our Algebra 1 course we don’t go into vertex form for a quadratic, but I thought my Honors students would pick it up pretty quickly based on their prior work with transformations and absolute value functions. So, I used this Henri Picciotto task “Make these Parabolas” as bellwork – first showing students a bit about vertex form with sliders on Desmos, then writing one equation of a graph as a class.

I turned them loose for about 5 minutes, and was super excited to see how many students were able to create the designs without any other instruction or help from me. (I even had a student ask me after class if there were more graphing challenges like this he could try. Don’t worry, I pointed him straight to Daily Desmos. 🙂 )

After the bellwork, students worked in groups of three on a packet with some questions about graphs of quadratics that came from the textbook. This included some of the skills we had worked on the day before, some questions where they were given the graphs and asked to write the zeros, vertex, axis of symmetry, domain and range, and some pretty straightforward application problems.

On the homework for my Honors class, I included a couple of challenge problems I was hoping would help them to connect what we already studied with quadratic formula and the discriminant to the graphs of quadratics.

**Thursday** – Review (entire quadratics unit, including solving equations)

**Friday** – Test

It was a good week. Only a few weeks of instruction remain before we begin preparing for the Algebra 1 End of Course Test. I’m grateful for sunny days and renewed energy to tackle the last few topics in the course.

I was thinking about symmetry the other day, and it got round to parabolas.

Imagine you have a picture of a parabola, just the line, no axes, no coordinates, no formula. The problem: Find the axis of the parabola. This turned out to be more of an engineering problem than a math problem!

Have a go!

By:

howardat58on 03.29.2015at 7:28 pm

This post should be called “the power of the MTBOS.” what an amazing curated list of great stuff that you have adapted, with stuff that you have added to round out a full unit! Such a cool diversity of activity that hits a lot of the important types of mathematical thinking. Kudos. And we’re reviewing quadratics in precal this week, so thanks for that too haha…

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Bowman Dicksonon 03.31.2015at 8:22 am

exactly! this is my superpower – finding, organizing, adapting, and seriously selling the awesome stuff that others have created and shared online. i’m so thankful to be a part of this community.

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rdkpickleon 03.31.2015at 11:25 am

Hello! I tried that “make these parabolas” thing, only with ALL conic sections and it was amazing. I had the kids work together so they had to communicate with each other, too, which added a nice element to it. I didn’t realize until reading that last comment that I was adapting something that you’ve already adopted : ) Thank goodness for the internet. Thanks for sharing all of this!

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multiplefactorson 04.18.2015at 3:27 pm