The intuitive simplicity of probability can be deceiving. Described is a dialogue that presents arguments for conflicting solutions to a seemingly simple problem determining the probability of having two boys in a two-child family knowing that one child is a boy. Solutions contain multiple arguments and representations. (MDH)

Two trigonometry problems are presented. The first compares the graphs of the functions arcsin[sin(x)], arccos[cos(x)], and the identity function f(x)=x. The second, using the law of cosines, demonstrates that the solution of a triangle knowing two sides and the excluded angle is no longer ambiguous. (MDH)

Abstract ideas in linear algebra are illustrated at different levels of difficulty through the investigation of the solution to a well-known puzzle. Matrices are used to model the puzzle and the concepts of rank, underdetermined systems, and consistency are employed in the solution to the problem. (MDH)

Great care must be taken when making the jump from the finite to the infinite. The concept of infinity is explored through a series of examples from infinite sequences, presenting potential contradictions that could occur from a natural extension of finding the fraction form of a repeating decimal. (MDH)

Reviews a body of psychological research which investigated children's errors in subtraction computations to assess whether the literature offers valuable, relevant information for those teaching subtraction and remedying student errors. It concludes that the research offers teachers little, so they must fall back on their knowledge and…

Presents activities utilized with primary teachers to alleviate instructional concerns about using calculators and provide reasons for using calculators in their mathematics instruction. Activities address the topics of estimation, number sense, numeration, whole number and fraction operations, probability, and problem solving. (MDH)

Presents the problem of finding the maximum area of a quadrilateral when three of the four sides are given. Incorporates several parts of the secondary school precalculus curriculum into the solution. Develops the formula to solve the problem. (MDH)

Presents an approach to the concept of absolute value that alleviates students' problems with the traditional definition and the use of logical connectives in solving related problems. Uses a model that maps numbers from a horizontal number line to a vertical ray originating from the origin. Provides examples solving absolute value equations and…

Discusses the equation and proportion methods for teaching how to solve percent problems. Supplements the teaching of each method by introducing a representational model that enhances understanding when solving percent problems. (MDH)

Explores the learning opportunities that might be created in mathematics instruction if reading were reconceptualized as described in the NCTM statement on communication. Develops the notion of "reading to learn mathematics" by enunciating and illustrating its key components. (44 references) (MDH)

A sampling of teachers (n=348) and principals (n=31) responded to a questionnaire designed to assess their beliefs about the effects of, experiences with, and impediments to calculator usage in elementary school mathematics. Results indicated that teachers expressed concern regarding negative effects of extensive calculator usage on mathematical…

Explores alternative strategies to solve algebraic equations that do not lend themselves to traditional methods. Examines one nontraditional equation by a graphical approach using a graphing utility and by a numerical approach using spreadsheets. Discusses new basic skills for algebra utilizing technology. Provides a computer program to solve…

Teaching the concept of integration differs depending on which of four perspectives is used to introduce the topic. Presents a method based on the historical development of the use of integration that introduces integral as antiderivative. Discusses examples of differential equations used in the development and ways to connect this to the other…

This evaluation study with 94 elementary students (50 with mild mental handicap) compared computer-assisted instruction (CAI) and paper-and-pencil practices in promoting automatization of basic addition and subtraction skills. Findings suggested CAI was more effective but that the students with mental handicap required more practice than…

Although rote learning is a heretical notion to many educators, memorizing, reciting, and drilling may be what is needed to improve test scores and provide students with the necessary skills for solving problems and developing complex thinking skills. Sidebars summarize direct-teaching methods for mathematics and a Core Knowledge curriculum…