Presents a public-key cryptosystem application to introduce students to several topics in discrete mathematics. A computer algorithms using recursive methods is presented to solve a problem in which one person wants to send a coded message to a second person while keeping the message secret from a third person. (MDH)

Shares a coded version of the number line to provide concrete experiences for learning abstract concepts. Using the fundamental theorem of arithmetic, appropriate coded symbols are determined for the prime factorization of each natural number and used to study the concepts of greatest common divisor, least common multiple, square roots, and…

Discusses two mathematical ideas that come from the Incan and Mayan cultures: (1) the quipus, an Incan recordkeeping tool that encoded data via a logical-numerical system on spatial arrays of colored, knotted cords; and (2) the link between recording time and counting in the Mayan culture. (MDH)

This book explains methods of representing information. Contents are divided into six chapters: (1) "Appetizers" includes activities that can be done individually to become familiar with the topics of signs, symbols, and codes; (2) "Concepts" provides a basis for symbol and sign development; (3) "Activities" features activities and classroom…

Described are some ways in which individual states code driver's license numbers. The encoding of month, date of birth, year of birth, sex, and others involving elementary mathematics and the use of an elaborate system of hashing functions in describing the first, middle, and last names are discussed. (KR)

Discusses the study of identification codes and check-digit schemes as a way to show students a practical application of mathematics and introduce them to coding theory. Examples include postal service money orders, parcel tracking numbers, ISBN codes, bank identification numbers, and UPC codes. (MKR)

Describes the Quipu, a mathematical device invented by the Incas of Peru that used the base-10 number system to store information. Suggests ways of incorporating material on the quipu into the arithmetic class. (MDH)

Cryptography is the science that renders data unintelligible to prevent its unauthorized disclosure or modification. Presents an application of matrices used in linear transformations to illustrate a cryptographic system. An example is provided. (17 references) (MDH)