### Race Car Math

If you've looked at any of Dan Meyer's Algebra or Geometry curricula on his blog, you'll notice he has "Race Car Math" throughout many of his Keynote slides. Since I couldn't put two and two together on this one nor find anything on his blog explaining it, I simply asked him.

My loving wife bought my son and me an RC Ferrari car for Christmas 2011 (featured in the 3 Act lesson Ferrari Ride), but I figured I'd invest a few bucks in a classroom RC car for Mr. Stadel's room. I made my way over to Toys "R" Us and spent less than \$15 on this bad boy. The remote is about the size of a crayon box and the car is about the size of a cantaloupe. It doesn't go crazy fast. It's just the right size and speed for a middle school student, boy or girl. This might be one of the best \$15 I've ever spent.

This week, we spent Wednesday reviewing linear systems in algebra and quadrilaterals in geometry. We have reviewed with Math Basketball numerous times this year and the ground rules are very similar. Check out Dan's Math Basketball directions if you need some guidance. Here's how I roll in my class. I toss a slide up with the following information. *The slide for my students is less text-heavy.
1. Work individually in your notebook (unless I announce "GROUP ANSWER" meaning students work with their group/table on their giant whiteboard).
2. Show all work.
3. Talking = DQ  (*talking during "group answer" is allowed)
4. One person stands with answer (all members of a group must stand before standing again).
5. 10 seconds with car:
1. Big box = 1 point
2. Medium box = 2 points
3. Small box = 3 points
When students are done solving a question you've thrown up on the board and most (if not all) groups have a representative standing, I usually call on the last person that stands up. They explain and/or give their answer. If any other person agrees with the answer, they sit down. I've already been circulating the room checking student work, so mentally I have a decent idea who has the correct work (answer) or not. If anyone is still standing, that means they disagree and have a different answer. I repeat this until every student sits down. If all groups have the same correct answer, I announce that. If there's one different answer, I (for time reasons) will demonstrate the correct solution while students watch in suspense to see who's correct.

Whoever stood and got the answer correct comes to the front of the room to represent their group in driving the car. If a person got it wrong, they are to stay at their desk and study the board so they can write down the correct solution or talk with someone around them for the correct solution. Since students must drive the car along an L-shaped path, they can follow it to the finish line. Here's what's at the finish line.

Students can drive the car into the largest box worth 1 point, or two other boxes with narrower openings worth two and three points. The 3-point box is the narrowest. In order for the team to get their points, they must enter the box (cross the plane) with the two FRONT tires before the end of 10 seconds. I count down. Ready. Set. GO!

We had a couple of groups somehow get two tires on the same side of the car in the box, but it didn't count. Set up your own rules. Whatever they are, stick to them. Many kids said they liked this better than math basketball. I can't blame them. You should see some of their shooting form. On second thought, you might not want to see their basketball form when shooting a nerf basketball. Scary!

My favorite exchange came from Chase in geometry who scored three points for his team with ease.
Student 1: "Chase, you're really good at that."
Chase: "Yea, I'm part of an RC car club."
Student 2: "Really?"
Chase: (sarcastically) "Yes, after school I practice driving RC cars."
Student 3: "Really Chase? Wow! Do you really?"
Chase: "Yes, I'm part of an RC car club." and sat down.
Chase remained straight-faced the entire exchange. Hilarious! I'm not sure if some students were still convinced he was part of an RC club, but he's not. Since this was my first time with Race Car Math, I'm happy how I kept fine-tuning it throughout the day to make it more efficient and student-friendly. For instance, with larger classes I said we would solve two questions first before racing the car. If they got both questions correct, their team would simply double the points of the box their car entered. If a team only got one question correct, they would get the box's points at face-value. This also allowed students to send up who they thought could best drive the RC car. For round two, that person could not drive again.

I found that the classroom dynamic and energy to be better when I did more "group answer" questions and students collaborated on their giant whiteboards. It's a win-win. They get to stand up, talk to each other, and collaborate just like any other day in class. Plus, I get to listen to them problem-solve, argue, agree, and cheer each other on.

*[Update] Here's an idea for the to-do list: Another way to play is have students accumulate correct answers for a sequence of approximately three questions. Each group earns 10 seconds with the car for every correct answer. Set the boxes up like goals on a soccer field, maybe 15 feet apart. If the group got three questions correct, they have 30 seconds to drive the car between boxes to score as many points as possible. If you test this one out before me, let me know how it goes.

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### Trashketball (2013 Pi Day task)

It all started with an episode of Suits on USA Network from January 31, 2013 (episode 213: Zane vs. Zane) where the opening scene has the two main characters (Harvey and Mike) playing a round of H-O-R-S-E trashketball in Harvey's office.  I jotted this one down on my digital "task ideas" list and knew it might have some potential later this year in Geometry. Here's Act 1:

Act 1: video to wonder and notice about
Act 2: teacher notes, and visual data/information to help solve the task
Act 3: visual confirmation of the practical answer
Sequel: additional tasks to explore (especially for early finishers) and teacher notes

I was going to chip away at this task until I realized Pi Day was coming up. Needless to say, I started working a little quicker. Ironically, in calculating the answer to the task, Pi can actually be divided by itself or "cancelled." I grabbed (bought, not shoplifted) two trashcans from Bed Bath & Beyond. I found the exact trashcan from Suits. Woohoo!!!! That circular truncated cone trashcan is so dreamy and transparent. I also found a cylindrical trashcan for my Geometry class. As you can see from Act 1, it's not transparent, but it'll get the job done. Measuring each dimension of the can was simple. Measuring the diameter of the trashketballs is a different story. I'm open to suggestions here. You'll find this in the "Teacher Notes"
How do you find the diameter of a trashketball? Have your students come up with ideas. Test those ideas. Make conjectures.
I crumpled up 8.5"x11" paper and made it as compact as possible. I took a handful of trashketballs and put them down on a ruler to get a rough mental mean of the diameters. Then I traced the best-fitting circle to measure the best-fitting diameter of each trashketball. I took the mean of these five diameters.
Seriously, I'm open to ideas. I quickly discovered that trashketballs are like snowflakes: no two are the same. However, I really started to perfect the form and process of making a trashketball. I'll admit, there's some buy-in with the trashketballs being perfect spheres. I'm okay with that. So maybe spend some time with your students perfecting the trashketball. Anyway, leave some ideas about measuring the diameter of the trashketballs in the comments, won't ya?

I'm looking forward to this task. My students occasionally play trashketball in my class with their scratch paper or class handouts (not necessarily mine) contributing to their idea of going paperless. I see this happening a lot on Thursday. Happy Pi Day!

Next up! The circular truncated cone trashcan. I'll start chipping away at having enough trashketballs for the circular truncated cone. Thanks in advance to the following people for helping with the volume of the circular truncated cone trashcan:
@mjfenton, @absvalteaching, @MaryBourassa, and @RobertKaplinsky.

Swish,
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### In the News!

Last Wednesday we had an awesome workday. Not only did we start on modifying the battery box to comply with the 2013 Solar Car Challenge Race Rules, but we also got interviewed by Doreen Hemlock and Taimy Alvarez from the Sun Sentinel. They wrote a terrific article about the Solar Knights and how we are raising \$30,000 for our cross-country race this summer, Texas to California. Please follow the link to view the article written by Doreen and photos captured by Taimy. We cannot thank them enough for getting our team out in the public and corporate view.

Photo by: Taimy Alvarez, Sun Sentinel