Students will review linear functions through a lab activity.

Students will find a linear relationship between the number of rubber bands and height.

5 minutes

Students will complete a quick Do Now where they will solve linear functions. As they are working, I will set up the materials needed for today's Lab Activity. I will place all of the materials, with the exception of the barbie dolls, in the front of the room in easy piles for students to access when the activity will begin.

We will quickly call out the answers to the Do-Now as a whole group.

70 minutes

This lesson was adapted from the NCTM website.

*Teaching Note: Each group will need an old Barbie Doll, rubber bands, masking tape, graphing calculators, and a yard stick. Additionally, the vertical height of a pre-determined location must be measured prior to the start of class. This location will be where Barbie completes her "jump", and should be kept from students until the end of class.*

Today's activity will quickly become a student and teacher favorite. We will be using linear functions and modeling to complete the Barbie Bungee Jump challenge.

First, I will open up today's Lab with a quick video of a bungee jumper.

I will then display students the Barbie Bungee Jump Presentation to describe the task for today's class. We will read through the needed materials and directions once as a group prior to the distribution of the materials. I will then encourage groups to get the materials that they will need from the front of the room, and to follow the instructions from the Presentation to complete the activity.

Even though we will review the directions once as a whole group, I think it is important to foster the skills that students need to complete activities like today's; I will provide as little direct instruction as possible, depending on the dynamic of the group. The Presentation will be left up on the screen and on additional computers in the classroom. If a group gets stuck, I will encourage them to revisit the Presentation to review the directions and pictures that depict the set-up of this activity.

Students will collect their data using the Barbie Bungee Data Sheet.

Each pair will move at a different pace, but I will wait until pairs have been working for at least 30 minutes to bring the class back together as a whole group. Once this is done, I will tell students the location and height of the site that Barbie will be bungee jumping. Students will then use rubber bands to fit the length of the Bungee Cord to the height that Barbie will need to safely complete the jump.

With the help of a co-teacher or other adult in the building, Pairs will split and one will be escorted to the bottom of Barbie's jump location. My classroom is on the second floor, so I completed my jump using a window. Each pair will go one at a time, with one throwing the Barbie out of the window, and the one on the ground measuring the lowest point that Barbie's head reached.

The pair that constructs a bungee cord that keeps Barbie alive, and closest to the ground will be the victor.

5 minutes

Once all students are back in the classroom, we will debrief our Barbie Bungee Lab. The questions below can be completed on paper, or as a whole group discussion.

- What did you learn?
- What went well?
- What was challenging?
- What assumptions did you make prior to starting?
- Were your assumptions met?
- Is there a relationship between the number of rubber bands used and the length Barbie drops?
- What role did linear functions play in the lab?
- Can you think of another situation that could be modeled with a linear function?

Students will complete this Reflection Activity for homework.