Did You Know?

Codes are used by our military and diplomatic forces to keep confidential information from unauthorized eyes. Businesses also send data that has been encoded to protect trade secrets and the privacy of their clients. The study of enciphering and encoding (on the sending end), and deciphering and decoding (on the receiving end) is called cryptography from the Greek (kryptos), or hidden and (graphia), or writing.

Navajo code talkers were some of the most famous code sleuths of the past century. When a Navajo code talker received a message, what he heard was a string of unrelated Navajo words. The code talker first had to translate each Navajo word into its English equivalent. Then he used only the first letter of the English equivalent in spelling an English word. To give an example, the word "Navy" in Navajo code would be "tsah (needle) wol-la-chee (ant) ah-keh-di-glini (victor) tsah-ah-dzoh (yucca)."

Design Challenge

Design a way to peer onto the secret hiding place of a super secret message without being caught. Have a teacher, parent or friend hide a secret message on top of a hiding place (a designated "high, out of reach place" will do just fine). Your mission is to find a way to read that message in a super sneaky way!

Constraints: You only have 20 seconds to get to the message and read it without being caught! Your device that you construct will need to be portable and must not leave a trace after you've left. The secret message must also be left intact in it's original location.

Extension: Design a super sneaky code, and translate the message that you have received from your teacher, parent or friend into your code. Then teach him or her how to use your code to decipher a message that you send back.

Materials: Anything that you can find at home or school to help you accomplish your mission.

Standards Addressed

(depending on student solutions)

Physical Science:
Grade 3: Light has a source and travels in a direction.

Grade 7: Light can be reflected, refracted, transmitted, and absorbed by matter; The angle of reflection of a light beam is equal to the angle of incidence.

Mathematical Reasoning (Grades 3-8):
Students make decisions about how to approach problems

Students use strategies, skills and concepts in finding solutions.

Measurement and Geometry:
Grade 3: Students choose and use appropriate units and measurement tools to quantify the properties of objects.

Grades 3 & 4: Students describe and compare the attributes of plane and solid geometric figures and use their understanding to show relationships and solve problems.

Grades 5 & 6: Students identify, describe, and classify the properties of, and the relationships between, plane and solid geometric figures.

Algebra1 (Grade 8):
Symbolic reasoning and calculations with symbols are central in algebra. Through the study of algebra, a student develops an understanding of the symbolic language of mathematics and the sciences. In addition, algebraic skills and concepts are developed and used in a wide variety of problem-solving situations.