Foam as a geometer

Foams are found everywhere: in nature, in technology, in our home. They are examples of cellular materials: assemblies or clusters of cells (from Latin cella: a small compartment or enclosed region) packed together so that they fill space without gaps. Foams come in different kinds. Ordinary liquid foam is an experimental system that solves some difficult geometry problems.

Plan des alten Judenfriedhofes von einem Kurmainzer Geometer [Illustration] : 1779

Scan von Monochrom-Mikroform

Lehrbuch der Vermessungskunde (Geodäsie) mit einer Sammlung von 153 gelösten Aufgaben und angewandten Beispielen zahlreichen Erklärungen. Unter Berücksichtigung des Selbstunterrichts für Geometer-Eleven, Studierende des Bau-, Berg- und Ingenieur-Fachs.

Mode of access: Internet.

Systematische Entwickelung der Abhängigkeit geometrischer Gestalten von einander, mit Berücksichtigung der Arbeiten alter und neuer Geometer über Porismen, Projections-Methoden, Geometrie der Lage, Transversalen, Dualität und Reciprocität, etc.

Mode of access: Internet.

Systematische Entwicklung der Abhängigkeit geometrischer Gestalten von einander : mit Berücksichtigung der Arbeiten alter und neuer Geometer über Porismen, Projections-Methoden, Geometrie der Lage, Transversalen, dualitätm und reciprocität, etc. /

First edition, Berlin, 1832.

Thinking in three dimensions: Exploring students' geometric thinking and spatial ability with the Geometer's Sketchpad

Current reform initiatives recommend that geometry instruction include the study of three-dimensional geometric objects and provide students with opportunities to use spatial skills in problem-solving tasks. Geometer's Sketchpad (GSP) is a dynamic and interactive computer program that enables the user to investigate and explore geometric concepts and manipulate geometric structures. Research using GSP as an instructional tool has focused primarily on teaching and learning two-dimensional geometry. This study explored the effect of a GSP based instructional environment on students' geometric thinking and three-dimensional spatial ability as they used GSP to learn three-dimensional geometry. For 10 weeks, 18 tenth-grade students from an urban school district used GSP to construct and analyze dynamic, two-dimensional representations of three-dimensional objects in a classroom environment that encouraged exploration, discussion, conjecture, and verification. The data were collected primarily from participant observations and clinical interviews and analyzed using qualitative methods of analysis. In addition, pretest and posttest measures of three-dimensional spatial ability and van Hiele level of geometric thinking were obtained. Spatial ability measures were analyzed using standard t-test analysis. ^ The data from this study indicate that GSP is a viable tool to teach students about three-dimensional geometric objects. A comparison of students' pretest and posttest van Hiele levels showed an improvement in geometric thinking, especially for students on lower levels of the van Hiele theory. Evidence at the p < .05 level indicated that students' spatial ability improved significantly. Specifically, the GSP dynamic, visual environment supported students' visualization and reasoning processes as students attempted to solve challenging tasks about three-dimensional geometric objects. The GSP instructional activities also provided students with an experiential base and an intuitive understanding about three-dimensional objects from which more formal work in geometry could be pursued. This study demonstrates that by designing appropriate GSP based instructional environments, it is possible to help students improve their spatial skills, develop more coherent and accurate intuitions about three-dimensional geometric objects, and progress through the levels of geometric thinking proposed by van Hiele. ^

O estado da arte na investigação sobre a utilização de software educativo para o ensino da matemática

Dissertação para obtenção do Grau de Mestre no Ensino de Matemática no 3º ciclo do Ensino Básico e do Secundário

Estudio de una estrategia didáctica basada en las nuevas tecnologías para la enseñanza de la Geometría.

Mejorar la enseñanza y aprendizaje de la Geometría Métrica en la formación de maestros de Educación Primaria. 40 alumnos de 3õ de Educación Primaria de la Facultad de Educación de la Universidad Complutense de Madrid. El grupo de alumnos que componen la muestra es dividido en dos subgrupos, A y B. En el primero se desarrolla una estrategia didáctica que incorpora el programa informático Geometerïs Sketchpad para la enseñanza de la Geometría Métrica. Por su parte, el subgrupo B utiliza una metodología tradicional, basada en exposiciones teóricas en la pizarra. Se obtienen datos cualitativos y cuantitativos con los que se realiza una comparativa entre los dos tipos de estrategias didácticas. Se distinguen dos grupos de instrumentos según el tipo de datos recogidos. Para la obtención de datos relacionados con la Geometría Métrica, se utilizan pruebas objetivas, ejercicios matemáticos, cuestionarios y exámenes. Los datos generales, relacionados con aspectos como la motivación, el interés y el grado de satisfacción de los alumnos, se obtienen a partir de entrevistas, encuestas y notas de campo. El método de investigación es el estudio de casos. Además, se utilizan dos técnicas para validar los resultados. Por un lado, la triangulación de datos, que consiste en contrastar y analizar la información mediante el uso de herramientas como las encuestas, pruebas objetivas y entrevistas. Por otro lado, se usa la triangulación de investigadores, a través del análisis comparativo del investigador de campo. El programa Geometerïs Sketchpad favorece la interactividad en la enseñanza, promueve el protagonismo del alumno en su aprendizaje y evita los trabajos repetitivos y rutinarios, aportando más tiempo a los contenidos esenciales. Además, facilita un tipo de aprendizaje activo y por descubrimiento, que permite utilizar distintas estrategias de resolución, fomenta la colaboración y se adapta a las necesidades de cada alumno. Se aporta una estrategia de enseñanza y aprendizaje que tiene dos características fundamentales. Por un lado, la existencia de una nueva organización didáctica de la Geometría que parte de la teoría de la construcción del conocimiento de tipo computacional. Por otro lado, la incorporación del programa Geometer's Sketchpad, junto con la resolución de situaciones problema y el uso de Internet.

Bressonianos: comprovando a influência do fotógrafo francês Henri Cartier-Bresson sobre fotojornalistas brasileiros atuais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eduard Study (1862-1930) - ein mathematischer Mephistopheles im geometrischen Gärtchen

Diese Arbeit befasst sich mit Eduard Study (1862-1930), einem der deutschen Geometer um die Jahrhundertwende, der seine Zeit zum Einen durch seine Kontakte zu Klein, Hilbert, Engel, Lie, Gordan, Halphen, Zeuthen, Einstein, Hausdorff und Weyl geprägt hat, zum Anderen in ihr aber auch für seine beißenden und stilistisch ausgefeilten Kritiken ebenso berühmt wie berüchtigt war. Da sich Study mit einer Vielzahl mathematischer Themen beschäftigt hat, führen wir zunächst in die von ihm bearbeiteten Gebiete der Geometrie des 19. Jahrhunderts ein (analytische und synthetische Geometrie im Sinne von Monge, Poncelet, Plücker und Reye, Invariantentheorie Clebsch-Gordan'scher Prägung, abzählende Geometrie von Chasles und Halphen, die Werke Lie's und Grassmann’s, Liniengeometrie sowie Axiomatik und Grundlagenkrise). In seiner darauf folgenden Biographie finden sich als zentrale Stellen seine Habilitation bei Klein über die Chasles’sche Vermutung, sein Streit mit Zeuthen darüber als eine der Debatten der Mathematischen Annalen (aus der er historisch zwar nicht, mathematisch aber tatsächlich als Gewinner hätte herausgehen müssen, wie wir an der Lösung des Problems durch van der Waerden sehen werden) und seine Auseinandersetzungen als etablierter Bonner Professor mit Engel über Lie, Weyl über Invariantentheorie, zahlreichen philosophischen Richtungen über das Raumproblem, Pasch’s Axiomatik, Hilbert’s Formalismus sowie Brouwer’s und Weyl’s Intuitionismus.

Two Remarkable Points of the Triangle Geometry

It is shown in the paper the discovery of two remarkable points of the triangle by means of “THE GEOMETER’S SKETCHPAD” software. Some properties of the points are considered too.

Connecting visual and analytic reasoning to improve students' spatial visualization abilities: A constructivist approach

Current reform initiatives recommend that school geometry teaching and learning include the study of three-dimensional geometric objects and provide students with opportunities to use spatial abilities in mathematical tasks. Two ways of using Geometer's Sketchpad (GSP), a dynamic and interactive computer program, in conjunction with manipulatives enable students to investigate and explore geometric concepts, especially when used in a constructivist setting. Research on spatial abilities has focused on visual reasoning to improve visualization skills. This dissertation investigated the hypothesis that connecting visual and analytic reasoning may better improve students' spatial visualization abilities as compared to instruction that makes little or no use of the connection of the two. Data were collected using the Purdue Spatial Visualization Tests (PSVT) administered as a pretest and posttest to a control and two experimental groups. Sixty-four 10th grade students in three geometry classrooms participated in the study during 6 weeks. Research questions were answered using statistical procedures. An analysis of covariance was used for a quantitative analysis, whereas a description of students' visual-analytic processing strategies was presented using qualitative methods. The quantitative results indicated that there were significant differences in gender, but not in the group factor. However, when analyzing a sub sample of 33 participants with pretest scores below the 50th percentile, males in one of the experimental groups significantly benefited from the treatment. A review of previous research also indicated that students with low visualization skills benefited more than those with higher visualization skills. The qualitative results showed that girls were more sophisticated in their visual-analytic processing strategies to solve three-dimensional tasks. It is recommended that the teaching and learning of spatial visualization start in the middle school, prior to students' more rigorous mathematics exposure in high school. A duration longer than 6 weeks for treatments in similar future research studies is also recommended.

The Effects of the Use of Technology In Mathematics Instruction on Student Achievement

The purpose of this study was to examine the effects of the use of technology on students’ mathematics achievement, particularly the Florida Comprehensive Assessment Test (FCAT) mathematics results. Eleven schools within the Miami-Dade County Public School System participated in a pilot program on the use of Geometers Sketchpad (GSP). Three of these schools were randomly selected for this study. Each school sent a teacher to a summer in-service training program on how to use GSP to teach geometry. In each school, the GSP class and a traditional geometry class taught by the same teacher were the study participants. Students’ mathematics FCAT results were examined to determine if the GSP produced any effects. Students’ scores were compared based on assignment to the control or experimental group as well as gender and SES. SES measurements were based on whether students qualified for free lunch. The findings of the study revealed a significant difference in the FCAT mathematics scores of students who were taught geometry using GSP compared to those who used the traditional method. No significant differences existed between the FCAT mathematics scores of the students based on SES. Similarly, no significant differences existed between the FCAT scores based on gender. In conclusion, the use of technology (particularly GSP) is likely to boost students’ FCAT mathematics test scores. The findings also show that the use of GSP may be able to close known gender and SES related achievement gaps. The results of this study promote policy changes in the way geometry is taught to 10th grade students in Florida’s public schools.

GeoGebraTUTOR : développement d’un système tutoriel autonome pour l’accompagnement d’élèves en situation de résolution de problèmes de démonstration en géométrie plane et genèse d’un espace de travail géométrique idoine

Travaux d'études doctorales réalisées conjointement avec les travaux de recherches doctorales de Nicolas Leduc, étudiant au doctorat en génie informatique à l'École Polytechnique de Montréal.

GeoGebraTUTOR : développement d’un système tutoriel autonome pour l’accompagnement d’élèves en situation de résolution de problèmes de démonstration en géométrie plane et genèse d’un espace de travail géométrique idoine

Travaux d'études doctorales réalisées conjointement avec les travaux de recherches doctorales de Nicolas Leduc, étudiant au doctorat en génie informatique à l'École Polytechnique de Montréal.