In this article we study a specific lattice classification of converse quadrilaterals, based on the relations between diagonals. This lattice contains 16 = 2[superscript 4] elements, which form a hypercube, and therefore it is a Boolean lattice. "Complementary" species of quadrilaterals thus appear and may be related in the lattice diagram. We…

Although ITSs are supposed to adapt to differences among learners, so far, little attention has been paid to how they might adapt to differences in how students learn from help. When students study with an Intelligent Tutoring System, they may receive multiple types of help, but may not comprehend and make use of this help in the same way. To…

This study examines the impact of successive versus non-successive scheduling of mathematics courses on the achievement of ninth-grade students in a suburban Oregon high school. The Oregon Assessment of Knowledge and Skills and student performance on the geometry course final exam were employed to compare the achievement of intact groups of…

What types of mathematical justifications do pre-service elementary teachers find convincing? To investigate this question, a task-based interview which was designed to elicit arguments of what students find convincing was administered to two female students who were enrolled in a geometry course at a large Midwestern university. These arguments…

Research on naive physics and naive optics have shown that people hold surprising beliefs about everyday phenomena that are in contrast with what they see. In this article, we investigated what adults expect to be the field of view of a mirror from various viewpoints. The studies presented here confirm that humans have difficulty dealing with the…

This article aims to present the changes in student selection and placement examinations in secondary education by focusing on the geometry content during the postreform period. The methodology, also used by Petway (2000), includes three steps toward the aim of examining the following: technical aspects, content coverage, and examination results.…

The article demonstrates that multiple solution tasks (MSTs) in the context of geometry can serve as a research instrument for evaluating geometry knowledge and creativity. Geometry knowledge is evaluated based on the correctness and connectedness of solutions, whereas creativity is evaluated based on a combination of fluency, flexibility, and…

Getting students to think about the relationships between area and perimeter beyond the formulas for these measurements is never easy. An interesting, nonroutine, and accessible problem that will stimulate such thoughts is the Lattice Octagon problem. A "lattice polygon" is a polygon whose vertices are points of a regularly spaced array.…

The process of developing definitions is underemphasized in most mathematics instruction. Investing time in constructing meaning is well worth the return in terms of the knowledge it imparts. In this article, the authors present a third approach to "defining," called "constructive." It involves modifying students' previous understanding of a term…

We present a simple and pedagogical derivation of the quantum adiabatic theorem for two-level systems (a single qubit) based on geometrical structures of quantum mechanics developed by Anandan and Aharonov, among others. We have chosen to use only the minimum geometric structure needed for the understanding of the adiabatic theorem for this case.…

We present a sequence of classroom activities on Euclidean geometry, both plane and space geometry, used to make three dimensional geometry more catchy and simple. The activity consists of a guided research activity that leads the students to discover unexpected properties of two apparently distant geometrical entities, quadrilaterals and…

As calls are made for reasoning-and-proving to permeate school mathematics, several textbook analyses have been conducted to identify reasoning-and-proving opportunities outside of high school geometry. This study looked within geometry, examining six geometry textbooks and characterizing not only the justifications given and the…

Take a strip of paper and fold a crease intersecting the long edges, creating two angles. Choose one edge and consider the angle with the crease. Fold the opposite edge along the crease, creating a new crease that bisects the angle. Fold again, this time using the newly created crease and the initial edge, creating a new angle along the chosen…

Mathematics is full of surprises and beauty. In this article, the author discusses three favourite topics that he finds both amazing and amusing: (1) the problem of the possibility of subdividing a rectangle into a number of different squares; (2) the arrangement formed when several soap bubbles meet; and (3) circles and spheres.

Kinesthetic intelligence is one of the seven kinds of intelligence identified by Gardner's multiple intelligence theory (1983). The kinesthetic approach to teaching has numerous pedagogical advantages and can be adapted to the teaching of mathematics. This article describes a series of kinesthetic activities designed to explore the properties of…