Activities which can be used to explore arrangements of five-sided polygons to cover a plane with no spaces are suggested. Sample tessellations are provided. Instructional methods involving this concept are discussed. (CW)

Described is automata theory which is a branch of theoretical computer science. A decomposition theorem is presented that is easier than the Krohn-Rhodes theorem. Included are the definitions, the theorem, and a proof. (KR)

Discussed is the use of magic squares as examples in a first year course in linear algebra. Four examples are presented with each including the proposition, the procedure, and a proof. (KR)

Presented is a method of interchanging the x-axis and y-axis for viewing the graph of the inverse function. Discussed are the inverse function and the usual proofs that are used for the function. (KR)

Discussed are the vital properties that an operator must have to be called a derivative and how derivatives work. Presented is an extension of the derivative that uses least squares to find the line of best fit. (KR)

Described is a way to illustrate cyclic and dihedral groups through symmetry using corporate logos and hubcaps. Examples of the different kinds of symmetry groups are explained in terms of Leonardo's Theorem. (KR)

Presented is a way of extending the list of rotation groups to include all finite subgroups of symmetries of the sphere, up to conjugation in its full group. Included is Klein's method for enumeration of the finite subgroups. (KR)

Presented is a game using different types of dominoes that represents growth of seeds from the beginning of the universe. Included are diagrams of the types of seeds, instructions, and examples of the game play. (KR)

Describes how an interview project used in conjunction with a primary sources based curriculum enhanced history learning. Students were involved in gaining information from community citizens. Outlines the procedures involved in the interviewing process and discusses the benefits to students including increased content acquisition, skills, and…

Interest in mathematics can often be generated by seemingly nonmathematical items. A card trick from a course in recreational mathematics for middle school students is described. It involves several important mathematical activities: problem-solving analysis, making a conjecture and testing it, discovering, and verbalizing. (MNS)

A four-scene skit is presented which is designed to increase knowledge and understanding of how AIDS is transmitted, to describe the control measures necessary to prevent the spread of the disease and to increase awareness of what life would be like living with AIDS. Discussion questions follow the skit. (IAH)

Discussed is an application of number theory to cryptology that can be used with secondary school students. Background on the topics is given first, followed by an explanation for use of the topic. (MNS)

The focus is on using mathematical concepts and operations to decode holiday messages. Worksheets are provided for levels one-two, three-four, five-six, and seven-eight. (MNS)

Presents an interactive classroom technique to help students understand how the market can be used to arrive at a cost-effective method for pollution control. Emphasizes the understanding of the fundamental ideas that the optimal level of pollution is rarely zero and that marketable pollution permits are efficient means of control. (KO)

Some activities with tangrams and their use for investigating fractions, constructions, and percentages are presented, with worksheets included. (MNS)