Research supported by a grant from the National Science Foundation. (DD)

Research supported by a Public Health Service grant from the National Institute of General Medical Sciences. (DD)

Four worksheets are provided which give instructions for constructing a tangram by locating points on the Cartesian plane, which specify shapes to be made with the seven tangram pieces, and which ask students to create additional shapes. (DT)

A Math Rummy card game, a stock market enrichment activity, and a puzzle in logical reasoning, all used with seventh and eighth graders, are described; directions for constructing a clock with suggestions for its use at the first grade level are given. (DT)

A method of two-stage clustering of literature based on citation frequency is applied to 5,065 articles from 57 journals in environmental and civil engineering. Results of related methods of citation analysis (hierarchical graph, clustering of journals, multidimensional scaling) applied to same set of articles are compared. Ten references are…

The lesson details an approach to teaching positive and negative numbers which uses number pairs and generates inverses that initially avoid any mention or use of negative signs. The material moves pupils from development of key concepts to the use of more standardized notation for number operations. (MP)

The approach discussed intuitively illustrates how a problem can be analyzed by breaking it down into parts. The method makes extensive use of graphs of absolute value functions and is broken down into three stages. Each stage is covered in some detail. (MP)

The usual methods for solving quadratic equations are noted to require either the use of numerical formula or curve plotting on graph paper. The method described here enables pupils to solve equations using only a 45 degree setsquare, graph paper, and a pencil for those which have both real roots and real coefficients. (Author/MP)

In a previous article in this journal (Vol. 17, p358, 1979), a wet-bulb depression table was recommended for two simple experiments to determine relative humidity. However, the use of a graph is suggested because it gives the relative humidity directly from the wet and dry bulb readings. (JN)