The Mayan system of numeration, which used 20 as the base, is discussed. The material presented has been used to stir the curiosity of students in different systems of numeration. It has been helpful in promoting a speedier and better understanding of base 10. (MP)

Examples of four interviews are presented to serve as sample evidence in support of more comprehensive diagnostic procedures in assessing reliably and validly the weaknessess and strengths of learners. The search for computational errors is seen to go beyond standard paper and pencil tests. (Author/MP)

Ways in which bead strings can be used for reinforcement and concept development are noted. After discussion on how to make bead strings, the material looks at: (1) prenumber concepts; (2) more than, less than; (3) conservation of number and numerals and numerousness; (4) addition and subtraction; and (5) place value. (MP)

This discussion deals with the question, are there integral rectangles such that a box of maximum volume is obtained by removing an integral-sided square from each corner? An equation to solve the problem is generated and a table of values presented. The material appears suitable for beginning calculus students. (MP)

Details of an instructor's attempt to solve a problem in combinatorics taken from a textbook used by some of his students are presented. It is felt the material raises a number of significant points about problem solving and mathematics. Teachers are encouraged to put themselves in such situations. (MP)

Three studies of college students found a sex difference in the correlation of memory scanning rate, short- and long-term components of free recall, and word recognition with memory span. Findings are discussed in terms of prior work and a theory presented to account for the obtained sex differences. (Author/RD)

Masters of three worksheets are provided which require students to name selected polygons, compute areas of triangles, rectangles, squares, and trapezoids, and compute cost per square unit. (MK)

Three alternative methods of finding averages of two numbers are presented. (MP)

An introductory multiplication lesson, used successfully with second graders, is detailed. The method takes advantage of prior knowledge acquired in a geometry unit of study. The lesson is seen to have potential for other grades teaching multiplication for remedial work, and explaining the commutative law. (MP)

Ideas are presented regarding: (1) unique learning activities for students who have difficulty with operations with signed numbers; (2) a mathematical inspection of a unique card trick that can be expressed as an equation; and (3) sketching of graphs of composite trigonometric functions. (MP)

The use of money to teach mathematical topics such as fractions, percents, decimals, and nondecimal numeration is encouraged. (MP)

Examples of student-developed methods for dividing fractions and dividing and multiplying whole numbers are presented. Both are selected to show mathematical creativity in general mathematics students which would often be overlooked. (MP)

Problems focusing on number theory that can make good use of the calculator in discovering and proving simple theorems are proposed. The focus is on the properties of subtracting the smaller of a three digit number and its mirror number from the larger in a process that leads to zero. (MP)

Activities and manipulative materials that teach pupils regrouping, also known as borrowing or carrying, are reviewed. Several examples of typical student errors and the reasons for these mistakes are outlined. (MP)

Learning activities using a two-pan balance to teach the concept of equality are described. Construction of a poster board balance is illustrated. (MP)