The students learn about body matches, measuring one part of the body using another body part. They learn about non-standard measures and relative measurement. This activity is motivated by a Cyberchase episode in which the CyberSquad must act as crime scene experts to find out who kidnapped Chewcrocca, a giant cybercrocodile.
Part I: Learning Activity
1. Ask the students to pretend that they are Crime Scene Explorers (CSE's) who find only two clues to catch the kidnapper. To do this, CSE's use "Body Matches." A body match is when one part of a person's body is used to measure another part of that person's body. What's neat is that this comparison, or "ratio" as it's called, works whether you're big or small. For example, with one of your hands, stretch out the distance between your thumb and middle finger of your hands and wrap it around the wrist of your other hand. Does the distance from the tip of your thumb to the tip of your middle finger measure your wrist?
2. Tell the students that they will watch a video that shows how the CyberSquad figured out how to identify the kidnapper using body matches. As students watch the video segment, ask them to write down the relationships among these measures of body parts. After they watch the video, they will test the relationships.
3. Distribute the Measuring with Body Matches handout.
4. Show the Body Matches QuickTime Video.
5. Note: the correct (approximate) relationships are:
a. one thumb-to-middle finger length = 1 wrist
b. two thumb-to-middle finger lengths =1 neck
c. three thumb-to-middle finger length = 1 head
d. 7 foot lengths (footsteps) = 1 height
e. 7 foot lengths (footsteps) = 1 arm span
f. 1 arm span = 1 height
6. Give the students string and have them check these relationships. Students can cut string to their desired lengths based on their needs for the activity. Emphasize that because these are 'relative' to one's own body, they should work whether they are tall or short. Ask students of differing heights to demonstrate the relationships.
7. Ask students if they can find any other body matches.
8. Tell students that they will watch another video segment in which the CyberSquad uses body matches to identify the kidnapper.
9. Show the Catching the Kidnapper QuickTime Video.
10. Discuss how the CyberSquad figured out which character was the kidnapper and whether or not they think the CyberSquad identified the correct person.
Part II: Assessment
Assessment: Level A (proficiency): Students are asked to estimate various body measurements using information regarding body matches.
Assessment: Level B (above proficiency): Students are given body matches for a criminal profile and asked to estimate the length of the kidnapper's other body parts.