Then I give them a chart with the number of rubber bands and cm she bungeed. (Is that a real word? Well I guess if my 6th graders can go around calling a pen a "frindle" then I can say bungeed.)
We talk about how to eye-ball the measurement of the farthest point to which she fell. Then they enter it on their chart. They do this for as many times as she doesn't die (hit the ground) in my class. Barbie has been known to bungee jump from desks, tv carts, file cabinets, door frames, the SmartBoard ...
Once Barbie is out of options in the classroom, we make a plot chart of the data, adding a line of best fit.
Students must then calculate how many rubberbands they will need to get Barbie to jump the required distance so that she ends in the "green zone" on the meter stick at the bottom of the playground equipment. This means Barbie had the ultimate thrill. If she hits the ground she's dead. If she only makes it to the yellow zone on the meter stick, well it wasn't really fun. If she's in the pink or didn't make it to the tip of the meter stick at all, she's fuming mad and wants a refund!