Atribuição de significado ao conceito de proporcionalidade: contribuições da história da matemática

This study is the result of a work which approaches the Mathematics History how source of the meaning s attribution in the proportionality concept. We adopt the methodology of the source qualitative and we work with a group of teachers from instruction s public system of the fundamental and medium level from Pocinhos City Paraíba. For the data collection, we use the field notes, the questionnaire, a sequence of activities and the interview semistructured like instruments. The study had how objective to know the significates attributeds to proportionality concept through of the activity mediate from Mathematics History, besides to investigate if a approach of the nature enables modification according to this sense. The results obtaineds though the data analysis indicate that the activities bring contributions which refer to achieve objectives. On the other hand they also showed that we have a long trajectory to be trailed in the meaning of to turn the Mathematics History a subsidy effective in the teachers practice, in view of the formation absence in the knowledge area, besides the necessity of the approach adequated of the Mathematics History in the didatics books of Mathematic

Vídeo-aula de história da matemática: uma possibilidade didática para o ensino de matemática

In this work we are disagreeing with the possibility of production and of the use of video-class for the disciplines of history of mathematics by the teachers of elementary e middle school as a way to contribute to the development of their classes. Our goal is to provide to the mathematics teachers the option of connecting social, scientific, cognitive, and didactic aspects of topics in math thoughts to their students. That shall be based in the presence of mathematics in the history of humanity. Thus, we consider possible that teachers and their students can link and relate mathematics to other sciences, education culture, and reflect about the many ways of represent them, as well as the patters of organization of nature and of culture. In this way, they shall be able to observe and interpret situations that involve mathematical questions associated to the various means of historic-epistemological studies already done by other researchers and scholars in the field of history of mathematics who works in creating video-classes. In addition to that, we can use all the available media in order to give edifying dynamics to the mathematical formulations established throughout history. In this sense, we are based and focused on the objectives, which are sustained by educational computer technology, techniques for video making, as well as mathematical teaching proposals and the historical inquiring made by Mendes (2001, 2009a, 2009b). The validating experimentation allowed us to conclude that the techniques we used in the production of the history of mathematics video-classes proved they to be valid ones. They are able to be executed with the minimum of technological resources. In addition, they have the same efficacy as far as classroom use

Formação continuada de professores que ensinam matemática: o papel do ábaco na ressignificação da prática pedagógica

The present dissertation performs a study about abacus part on the continuous education of Elementary School s Mathematic teachers on what concerns the basic operations of addition and subtraction with (re)unification by using the manipulative and/or informatical abacus. Therefore, the research intends to answer the following question: How does a teacher reframe the pedagogical practice while teaching the Decimal Numeral System and the conventional operations of addition and subtraction with (re)unification through manipulative and informatical abacus? In order to do so, we rely ourselves on the Guy Brousseau s Theory of Didactic Situations (TDS) from 1996 that affirms the necessity to trace a way in accordance with the teaching situations that lead the student s learning; and on the work of Pierre Lévy (1993), in which the poles of communication oral, written and virtual create three ways of communication through which the learning process happens. The methodology of this paper was based on the Strategic Research-Action of Franco (2005). The didactic sequence was elaborated in accordance with TDS and used the manipulative and informatical abacus as didactic resource. With the application of the didactic sequence, it was verified that the continued formation of Elementary School s teachers concerning the operations of addition and subtraction on the initial years/levels is pertinent once it has been observed some difficulties of the teachers concerning this mathematical subject. Besides, the analysis of the didactic sequence has allowed one to realize that teachers had some difficulties concerning the numeric representation with order zero, the resolution of operations of addition and subtraction using the manipulative and informatical abacus and the realization of (re)unification on the subtraction with meaning. These observations has been discussed with the teachers and, after that, it has been done some didactic-methodological routings of the operations of addition and subtraction with re(unification) that contributes with the teaching and learning process.

Ensino de matemática pelo rádio (1950 1970): uma história falada e um documentário didático

This study aimed to describe and analyze aspects of the historical course of teaching Mathematics by Radio Experiences in Rio Grande do Norte, between the decades from 1950 to 1970 in order to organize a documentary (CD-ROM) containing information about Mathematics studied by Radio who have experienced it. In this, we use qualitative research. We seek support in the theoretical framework of cultural history and memory researchers as Certeau (1998), Chartier (1990), Le Goff (2008), Thompson (2002) and Peter Burke (2004). Moreover, we take the elements of oral history. We focus on the teaching of literacy and the primary of the Radio schools in two rural communities - Logradouro and Catolé - who are currently part of the city of Lagoa Salgada (RN) and, with respect to the Junior High School, we stopped in the Course of Madureza at Radio. We used as written sources, especially the documents found in the General Archives of the Archdiocese of Natal (RN) and the employees assigned by the participants of the survey. Our sources come from the oral testimonies of pupils and monitors Lagoa Salgada City, teachers, broadcasters and technicians of Rural Support Service (SAR) Natal (RN). In this study, we identify the geometry Cubação social practices of Lagoa Salgada students. Also identified in the research material, the Global Method with the pedagogy of Paulo Freire, that guided the production of lessons in literacy and primary courses. Content in Mathematics, we find traces of the trend-Empirical activist. In the course of Madureza, there was a tendency formal technique Fiorentini (1995). Finally, as a result of this study, organize and present a documentary (CD-ROM), along with the analysis of this study, containing the history of Mathematics teaching by Radio, from the speech of those who experienced Radio, emphasizing the methodology teaching developed in class, that serves as a reference material for students, professors and researchers.

Dificuldades na construção de gráficos de funções

This study describes about graduation s students difficulties of to draw functions graph. Specifically, we intend to observe their abilities evolution, as well as their difficulties during Calculus I subject in engineering course. For that, we show them publications about the elaboration of graphs and its difficulties in obstacle terms and some researches witch contain this subject and that it was done during postgraduate studies in mathematical education. It shows by research methodology aspects related to French didatic s mathematic and some theories of cognitive psychology considering the high value between theoretical-methodological relation that was evidenced in both theoretical conceptions about ways to understand and teach mathematic. This methodology is based on didactic engineering purpose, that consist in preliminaries analysis, conception and didactic sequence analysis prior, trials by application followed analysis up and conclusion. We had also used pedagogicals actions and analysis of results achieved, to classify types of errors made by the 2005 s students during second semester, from conceptions related to the episthemologic and didactics obstacles

Dimensão educativa do trabalho: estudo de caso da associação de bordadeiras do Seridó ABS- Caicó/ Rio Grande do Norte

This current work s contains issues about the educative dimension of work and its organization s process and managing for it own professionals. It aims to understand how the skills and pedagogic process, in a educative praxis perspective. Are based in a new culture of work of education process an work managing by workers in Handcraft Association of Serido/ Caicó/ RN. It uses as a methodologic-theoric reference cases s study approach, selecting the procedures of part extructure interview. It was done with six embroidereses from the Handcraft Association. The research shows that the educative process of learning and knowledges construction, in the work and by the work. Those processes develop in exchange experiences net in a friendly economic environment and raise elements of a work culture personal that work there. The embroidereses learn how to embroid doing the job and this learning, a lot of times, is influenced by the life conditions, residence local and infantile work in the country area and the living to the urban area, particularly to Caicó. The knowledge relation between them is the matter fact in the embroider learning process that means a social relation based on the knowledge differences between their position in its structure involving the work division, that each handcraft maker knows every part of the embroider, type of work or machine type, step by step until the work is done. It involves decision, execution and machine movements repetition, the focus are the categories that fit in current flexible financial issue. They schedule the work at home so they have time to do other stuff. Most part of the production currently is done to obey de a certain request that aims as production target, being a homework. Another important issue is the embroider work time: time and experience that is within in the professional life and its knowledge representation of job/profession. This time is got as a acquisition process of certain a work dominion and self knowing; time added to changes that were being there practicing from the new characteristics in the furniture, clothes and towels that are in the introduction communicative and its effect. In this way this work include articulations process among skills, educative process and handcraft work organization that allowed the interpretation and finish, that are related to the case study and its developments: handcraft embroidered considered as a profession, money source not conventional where is not work available and a temporary activity while studyng, homework and flexible work

Os jogos com regras na educação matemática inclusiva

This present study aimed to examine the use of games with rules in working with math education in regular classes included in Elementary School, in the municipal education schools of Natal/RN, observing the learning process and development of all students, especially those with disabilities. The theoretical references used are based on Vygotsky's works and other authors from the historical-cultural perspective, as well as researchers in the field of Inclusive Education and Mathematics Education. The investigation was based on the qualitative research guidelines, with the application of semi-structured interviews with educational coordinators and teachers from the schools involved as well as classroom observations, looking for, in the speeches of those involved and in their teaching practices, elements to reflect on the Mathematics Inclusive Education, the use of games with rules -starting from its goals, the participation of disabled students, the pedagogical mediations, up to its accessibility - and from the learning of disabled students. The analysis results showed that the concepts underlying the development of inclusive teaching practices still refer to the clinical-medical paradigm, understanding the student with disabilities from their deficiencies; which teachers use, in their majority, the mathematical games with rules in their classes, but which the teaching mediation, during these activities, still needs to be qualified so that they can, effectively, contribute to the learning and development of all students; students with disabilities do not always participate in games with others colleagues; games with rules are rarely accessible; and that the Universal Design principles are not adopted in the selected classrooms for this study. Thus, it is clear that much remains to be done so that Mathematics Education can contribute to the learning and development of all students, and among those actions the teacher continuing education is recommended

Estimativa da profundidade do embasamento na bacia potiguar usando inversão gravimétrica

The gravity inversion method is a mathematic process that can be used to estimate the basement relief of a sedimentary basin. However, the inverse problem in potential-field methods has neither a unique nor a stable solution, so additional information (other than gravity measurements) must be supplied by the interpreter to transform this problem into a well-posed one. This dissertation presents the application of a gravity inversion method to estimate the basement relief of the onshore Potiguar Basin. The density contrast between sediments and basament is assumed to be known and constant. The proposed methodology consists of discretizing the sedimentary layer into a grid of rectangular juxtaposed prisms whose thicknesses correspond to the depth to basement which is the parameter to be estimated. To stabilize the inversion I introduce constraints in accordance with the known geologic information. The method minimizes an objective function of the model that requires not only the model to be smooth and close to the seismic-derived model, which is used as a reference model, but also to honor well-log constraints. The latter are introduced through the use of logarithmic barrier terms in the objective function. The inversion process was applied in order to simulate different phases during the exploration development of a basin. The methodology consisted in applying the gravity inversion in distinct scenarios: the first one used only gravity data and a plain reference model; the second scenario was divided in two cases, we incorporated either borehole logs information or seismic model into the process. Finally I incorporated the basement depth generated by seismic interpretation into the inversion as a reference model and imposed depth constraint from boreholes using the primal logarithmic barrier method. As a result, the estimation of the basement relief in every scenario has satisfactorily reproduced the basin framework, and the incorporation of the constraints led to improve depth basement definition. The joint use of surface gravity data, seismic imaging and borehole logging information makes the process more robust and allows an improvement in the estimate, providing a result closer to the actual basement relief. In addition, I would like to remark that the result obtained in the first scenario already has provided a very coherent basement relief when compared to the known basin framework. This is significant information, when comparing the differences in the costs and environment impact related to gravimetric and seismic surveys and also the well drillings

A critical evaluation of the expression of parasitemia in experimental Chagas' disease

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

O conhecimento de polígonos e poliedros: uma análise do desempenho de alunos do ensino médio em exemplos e não-exemplos

O artigo pretende mostrar os resultados de uma pesquisa cujo objetivo foi analisar o desempenho de alunos do Ensino Médio na identificação de exemplos e não-exemplos de polígonos e poliedros, tendo em vista os atributos definidores e atributos irrelevantes. Participaram da pesquisa 253 alunos, distribuídos em três séries do Ensino Médio de uma escola pública, que responderam um teste de exemplos e não-exemplos. Posteriormente, foram selecionados seis alunos para serem entrevistados sobre seus conhecimentos a respeito dos exemplos e não-exemplos. Os resultados mostraram que os participantes obtiveram uma média baixa (M = 5,59) na tarefa que exigiu a identificação de exemplos e não-exemplos de polígonos e poliedros. A análise das entrevistas mostrou que a maioria dos alunos considerou que o atributo irrelevante dos polígonos analisados não interferiu na resposta. Contudo, evidencia-se, de modo geral, que esses alunos apresentaram um conhecimento conceitual longe do esperado para esse nível de ensino.

Construção e uso do pulverizador-logarítmico manual

Descreve-se a construção do pulverizador-logarítmico, seu funcionamento e gama de aplicações. Deduzem-se as fórmulas matemáticas em que o mesmo se baseia. Apresentam-se ábacos que permitem determinar a concentração de calda em qualquer ponto da área pulverizada.

Discalculia do desenvolvimento: avaliação da representação numérica pela ZAREKI-R

O presente estudo investigou aspectos da representação numérica (processamento numérico e cálculo) e memória operacional de crianças com transtornos de aprendizagem. Participaram 30 crianças de idade entre 9 e 10 anos, ambos os gêneros, divididas em dois grupos: sem dificuldade em aritmética (SDA; N=11) e com dificuldade em aritmética (CDA; N=19), avaliadas pela ZAREKI-R, Matrizes Coloridas de Raven, o Blocos de Corsi e o BCPR. Crianças CDA exibiram escores levemente mais baixos que as SDA quanto ao nível intelectual e nos Blocos de Corsi. Na ZAREKI-R apresentaram prejuízo nos subtestes ditado de números, cálculo mental, problemas aritméticos e total. Crianças CDA apresentaram déficits específicos em memória operacional visuoespacial e comprometimento em processamento numérico e cálculo, compatível com discalculia do desenvolvimento.

Genetic and environmental effects over milk production of buffalo cows in Brazil

The objective of this paper was to evaluate the relevance of environmental and genetics effects on milk production of buffalo cows in Brazil. The data were based on the Buffalo Genetic Improvement Program - PROMEBUL, using information of 1,911 cows (107 Jafarabadi, 101 Mediterranean, 1,056 Mu/Tab and 647 crossbred females) with parturition between 1982 and 2003. The mathematic model for evaluating milk production included the fixed effects of herd, parturition year (1982 to 2003) and month (January to December), calf's sex (male or female), genetic group (Jafarabadi, Mediterranean, Murrah, and crossbreed), number of milking (one or two), lactation order (1 to 12) and duration of lactation (as a linear effect). The mean milk production in herds was 1,590.36 +/- 609.25 kg. All sources of variation were significant (P<0.05) for the studied characteristics, except calf's sex. The mean milk production per genetic group was 1,651.4; 1,592.2; 1,578.3 and 1,135.5 kg, for Murrah, Mediterranean, Crossbred and Jafarabadi, respectively. The duration of lactation was the most important source of variation over milk production, followed by the year of parturition, herd, parturition order, genetic group and month of parturition.

Physical and postural aspects of teachers during work activity

Studies indicate that teachers constitute a professional segment, in which the work characteristics and the demands originating from the act of teaching, favor the emergence of sickness, concerning physical or emotional aspects. The present work aimed to describe physical and postural aspects during the working activity of teachers. A total of 120 elementary school teachers (1st to 8th grade) took part in the survey. For data collection, a questionnaire was applied: it included personal and occupational information, perception of discomfort and being off work; physical strength activities; posture at work and physical conditioning activities. The average age of teachers of the present sample corresponds to 35,8 years. In relation to activities which generate more physical strength, the answer none of the activities was predominant with 30 answers; followed by writing on the board, standing up during the period of classes, explanation of the subjects, class elaboration, correction of homework and others. The area of the body with higher amount of occurrences and prevalent discomfort referred to the lower limbs and spinal cord. These data inform the necessity of investing in prevention programs for the teachers, in order to develop strategies into the organizational context and interventions at the work environment.

Pesquisando Práticas e Táticas em Educação Matemática

The present article, which is one study among others, seeks to understand practices and tactics of day-to-day school, spanning and being spanned by three studies in Mathematics education. The diversity of scenes, people and strategies used by actors in everyday school, considered from the theoretical perspectives of Foucault and Deleuze, shed light on the ways Mathematic alphabetization takes place and evidence regarding what is present in the black box of school culture, in a constant problematization about what a school can do. Maps are presented that establish cartographies, revealing smooth and striated territories, on a path created by the research done in those schools, where life is always invented.