**Last summer I tried Barbie Zip Line and reported the experience**here. I also supported a handful of

*Math 8*teachers interested in Barbie Zip Line during the school when they explored the Pythagorean Theorem. I have to admit, with every experience, it always felt like it could be different, possibly better. This year, I went a different route and Part 1 just documents what I've done so far. Part 2 will be the conclusion.

**First, I avoided the Pythagorean Theorem (for now).**On Monday, my students already knew we would be starting Barbie Zip Line on Thursday. That was about as much information as I revealed. Everything else was structured to elicit as much student insight, information, and ideas as possible.

**I started by projecting this slide**:

Students discussed in their groups and a few shared whole group. I jotted down a few quick notes:

I love this informal language. Would this be an opportunity to work in slope? Maybe. I wouldn't force it as I'm confident we'll have plenty of other opportunities.

A few hands go up.Me: Has anyone her gone zip lining before.

Me: How would you describe it to someone in the class who has never been?

Katherine: Awesome!

Me: How would you describe what zip lining is to someone unfamiliar to it?

Katherine: You wear this harness. You ride down a line...

Mateo: You have two cables attached to you in case one of them breaks, there's a backup. Someone pushes you at the beginning and you ride along a cable...

Me: Great. Thanks. Would it help if we saw pictures or video of someone zip lining to give everyone a better perspective?

Everyone: YES!

Me: Here's what Google Images has for "zip line pictures".

Me: A good business model will provide their customers with a safe and thrilling experience. Therefore, I'd like you all to fill out this Google Form with the following prompts and questions:

- Briefly describe the characteristics of a DEATH zip line.
- Briefly describe the characteristics of a BORING zip line.
- Briefly describe the characteristics of a JUST RIGHT zip line.
- What information would be useful to know when building a zip line?
- If we had a small scale zip line in class, what data can we collect from the small scale?

**I'm fascinated by the results.**I learned I need to truly value, trust, and use my students' intuition

*way*more often and when launching a lesson/activity. Check out their results here. These results will help guide Desmos Part 2. However, first we need to do Desmos Part 1.

The actual zip line quad. |

**Desmos Part 1**

Students go to this Desmos graph and quickly create three zip lines.

**Once they are done,**they head over to this Padlet page and post their Desmos graph for their classmates (and me) to see.

**Desmos Part 2**

*

*I will post what students do in Barbie Zip Line (2015) Part 2*.

Before going outside, students begin doing a small scale version of the zip line inside the classroom. Here are the materials:

- 3 paper clips
- 2 measuring tapes
- 1 string (100 inches)
- iPad (for Desmos part 2)
- iPad or phone timer

Record their data inside of this pre-made Desmos template.

*If you go the route of the Pythagorean Theorem, adjust your table accordingly.**Here's a handout for each student.**After collecting their data, students will be expected to draw a pretty descriptive scale picture of their zip line on this handout. They'll also need to predict how long it will take their doll to complete her zip line ride.

**As you can see from the handout and expectations**, I'm placing a big emphasis on the following:

- Scale
- Proportional reasoning
- Rate of change (or slope)
- Rate

**No mention of Pythagorean Theorem**. Find out if it stays that way in my Barbie Zip Line (2015) Part 2 post, next week.

Zip 1,

1011

**P.S.**Most importantly, my son was really excited to visit my class today and partake in the Barbie Zip Line adventure. I was really excited too. DUH!