**Submitting Organization:** National Council of Teachers of Mathematics

**Grade Levels: **8th Grade

**Subject Area:** Math

**Standards Alignment: **Common Core State Standards

CCSS.MATH.CONTENT.8.F.B.4

**Description of the Activity: **

Tell students that they are going to design a bungee ride for Barbie. Explain the closer Barbie gets to the ground, the more thrilling it is for her. Ask students to explain the risk if they make the bungee cord too long (Barbie might hit her head and be seriously injured). Give each group a doll and 25-50 rubber bands. Explain to students that they need to figure out a way to collect data that will help them understand how many rubber bands to use in a bungee cord that will give Barbie a thrilling ride without killing her. Tell students you don’t yet know how long the actual drop will be.

**Discussion Questions:**

- Is the length of the drop the same as the length of the chain of rubber bands? (No, the rubber bands will stretch when Barbie drops)?
- How could you measure the length of the drop?
- Will the length of the drop change if you add more rubber bands?
- What are some good numbers of rubber bands to test out?
- If we decided to drop Barbie from a 20′ height, could you predict how many rubber bands would give her a long but safe drop?

**Resources Needed:**

- One small doll, stuffed animal, or action figure per group (heavier stuffed animals, like Beanie Babies, work best),
- About 25-50 rubber bands
- A yardstick
- A tape measure, or paper ruler
- Pencil and paper to record data, per group of 3-4 students.

**Link to further resources:**

http://illuminations.nctm.org/Lesson.aspx?id=2157 (from http://illuminations.nctm.org; also part of http://mathforum.org/emc/)