This paper discusses a result of Li and Shen which proves the existence of a unique periodic solution for the differential equation x[dots above] + kx[dot above] + g(x,t) = [epsilon](t) where k is a constant; g is continuous, continuously differentiable with respect to x , and is periodic of period P in the variable t; [epsilon](t) is continuous…

In this article, the authors present a laboratory exercise in data collection and statistical analysis in biological space using clustered stomates on leaves of "Begonia" plants. The exercise can be done in middle school classes by students making their own slides and seeing imprints of cells, or at the high school level through collecting data of…

Cross-sectional and longitudinal data from students as they advance through the middle school years (grades 6-8) reveal insights into the development of students' pattern generalization abilities. As expected, students show a preference for lower-level tasks such as "reading the data," over more distant predictions and generation of abstractions.…

A study of the effect of science teaching with a multimedia simulation on water quality, the "River of Life," on the science conceptual understanding of students (N = 83) in an undergraduate science education (K-9) course is reported. Teaching reality-based meaningful science is strongly recommended by the National Science Education Standards…

Learner centred design methods highlight the importance of involving the stakeholders of the learning process (learners, teachers, educational researchers) at all stages of the design of educational applications and of refining the design through an iterative prototyping process. These methods have been used successfully when designing systems…

The purpose of this study was to determine the effect of the TI-81 Graphics Calculator as an instructional tool on college algebra students' conceptual and procedural achievements involving functions and graphs and on the students' attitudes toward mathematics. The study was a posttest-only, equivalent control group design conducted with students…

The normal curve has long been important in statistics. Most interval variables yield normal or quasi-normal distributions when data are collected from large samples, and the normal "Z" distribution is also used as a test statistic (e.g., to test differences between two means when sample size is large, since "t" approaches…

Using a computer equipped with a plotter, graphs of linear equations and trigonometric identities can be produced. Examination of these graphs can aid in teaching solution of equations. (SD)

Two approaches to the teaching of logarithms are described. One is essentially algebraic while the other involves integration. (SD)

A dialogue between a student and a teacher is presented. The topic is the absolute value function. The discussion ranges from elementary algebraic properties to deeper properties of the function. (SD)

Similarity of parabolas and other conic sections is discussed. The theorem "Any two parabolas are similar" is deduced. (SD)

Using a set of worksheets, students will discover and apply Euler's formula regarding connected planar graphs and play and analyze the game of Sprouts. One sheet leads to the discovery of Euler's formula; another concerns traversability of a graph; another gives an example and a game involving these ideas. (Author/KM)

This article describes a series of activities and worksheets to provide students with experience in graphing number pairs. Students at different lev els can use the activities to relate basic arithmetical operations to graphs. (Worksheets are included.) (SD)