Syftet med den empiriska studien är att undersöka lärares användning av konkret material i matematikundervisningen. I studien undersöks vilket konkret material som läraren använder, hur det konkreta materialet används och i vilka undervisningssituationer som läraren hänvisar till konkret material. Genom observationer av fyra olika lärare, i fyra olika klassrum har vi fått svar på studiens frågeställningar. Med hjälp av rational number projekt och Heddens teori har resultatet analyserats. Resultatet visar att konkret material är framgångsrikt för elever när det ska gå från konkret till abstrakt förståelse inom matematik. Resultatet visar även att det är viktigt att variera mellan olika representationer i undervisningen. De olika representationerna som framgick i observationerna är bilder, verkliga situationer samt talade och skrivna symboler.

This study engaged fourth and fifth graders in solving a set of proportional tasks with focused discussion and concept development by the teacher. In order to understand the students’ ability to generalize the concept, they were asked to write problems that reflected the underlying concepts in the tasks and lessons. A qualitative analysis of the student generated problems show that the majority of the students were able to generalize the concepts. The analysis allowed for a discussion of problems solving approaches and a rich description of how students applied multiplicative reasoning in composing mathematics problems. These results are couched in a discussion of how the students solved the proportional reasoning tasks.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-08-24T13:21:38Z No. of bitstreams: 1 Fernanda Andrea Fernandes Silva.pdf: 2425640 bytes, checksum: 503cb9560b6d95b13d950e13a8ad6c9c (MD5) / Made available in DSpace on 2016-08-24T13:21:39Z (GMT). No. of bitstreams: 1 Fernanda Andrea Fernandes Silva.pdf: 2425640 bytes, checksum: 503cb9560b6d95b13d950e13a8ad6c9c (MD5) Previous issue date: 2013-03-05 / This research proposes to investigate what are the meanings and the representations of the rational numbers that are contemplated in the National High School Exam – ENEM. Therefore, then we take as reference the studies of Romanatto (1997) and Gomes (2010) and we adopted the following meanings for the rational numbers: measure (part-whole), quotient, reason, multiplicative operator, probability, a number in straight numerical and percentages. To we analyze the records of representations of the rational numbers that are contemplated in ENEM, We use the Theory of the Representations semiotics Raymond Duval who considers that mathematical objects are not directly perceptible and that access to them is possible only through a system of representation. The methodological route that we have adopted consisted of the two stages. In step I we analyze the tests general knowledge of the ENEMs 1998 to 2008 and math tests and their technologies of the ENEMs from 2009 to 2011, in the sense of identify items that mobilized the concept of rational numbers in their different meanings. In step II, we analyze the items identified in step I, regarding the math tests and their technologies of ENEM 2009 to 2011, as to records of representations contained in the structure of the item and in particular of the records of the rational numbers, and also, regarding as to records of representations, treatments and conversions that could be mobilized during the resolution of the item. We concluded that, in the evidence of general knowledge of the ENEMs 1998 to 2008, approximately 5.6% of the items (3.9 items per tests) involved the concept of rational numbers. While in math tests and their technologies of the ENEMs 2009 to 2011 (new ENEM), approximately 21% of the items (9.6 items per tests) mobilized this concept. The meanings identified in the items relative at the ENEM 1998 to 2008 were virtually the same identified in the period of the ENEM new, part-whole, reason, percentages and probability. Being the meaning, percentage, as the more addressed. Some items involved more than one meaning. The items related to math tests and their technologies of the ENEMs 2009 to 2011 had a predominance in its structure (enunciated, bracket, command, and alternatives of the answer), among the records of semiotic representations of rational numbers, the numeric registration, percentages. The semiotic register of rational numbers who else could be mobilized during for the resolutions of the items was the record fractional numerical. Conversions between the records of rational numbers only occurred in only one direction, with the exception of one item of the ENEM 2010. / Essa pesquisa se propõe a investigar quais são os significados e as representações dos números racionais que são contemplados no Exame Nacional do Ensino Médio – ENEM. Para tanto, tomamos como referência os estudos de Romanatto (1997) e Gomes (2010) e adotamos os seguintes significados para os números racionais: medida (parte-todo), quociente, razão, operador multiplicativo, probabilidade, um número na reta numérica e porcentagem. Para analisarmos os registros de representações dos números racionais que são contemplados no ENEM, utilizamos a Teoria das Representações Semióticas de Raymond Duval que considera que os objetos matemáticos não são diretamente perceptíveis e que o acesso a esses só é possível por meio de um sistema de representação. O percurso metodológico constou de duas etapas. Na etapa I analisamos as provas de conhecimentos gerais dos ENEM de 1998 a 2008 e as provas de matemática e suas tecnologias dos ENEM de 2009 a 2011, no sentido de identificar os itens que envolviam o conceito de números racionais nos seus diferentes significados. Na etapa II, analisamos os itens identificados na etapa I, referente às provas de matemática e suas tecnologias dos ENEM de 2009 a 2011, quanto aos registros de representações contidos na estrutura do item e, em particular os registros dos números racionais, e, também, quanto aos registros de representações, os tratamentos e as conversões que podiam ser mobilizados, durante a resolução do item. Concluímos que nas provas de conhecimentos gerais dos ENEM de 1998 a 2008, aproximadamente 5,6% dos itens (3,9 itens por prova) envolviam o conceito de números racionais. Enquanto que nas provas de matemática e suas tecnologias dos ENEM de 2009 a 2011 (novo ENEM), aproximadamente, 21% dos itens (9,6 itens por prova) abordavam esse conceito. Os significados identificados nos itens relativos aos ENEM de 1998 a 2008 foram praticamente os mesmos identificados no período do novo ENEM, parte-todo, razão, porcentagem e probabilidade. Sendo o significado porcentagem o mais abordado. Alguns itens envolveram mais de um significado. Os itens referentes às provas de matemática e suas tecnologias dos ENEM de 2009 a 2011tiveram um predomínio na sua estrutura (enunciado, suporte, comando e alternativas de resposta), entre os registros de representações semióticas dos números racionais, o registro numérico porcentagem. O registro semiótico dos números racionais que mais pôde ser mobilizado durante as resoluções dos itens foi o registro numérico fracionário. As conversões entre os registros dos números racionais, só ocorreram apenas num sentido, com exceção de um item do ENEM 2010.

This study engaged fourth and fifth graders in solving a set of proportional tasks with focused discussion and concept development by the teacher. In order to understand the students’ ability to generalize the concept, they were asked to write problems that reflected the underlying concepts in the tasks and lessons. A qualitative analysis of the student generated problems show that the majority of the students were able to generalize the concepts. The analysis allowed for a discussion of problems solving approaches and a rich description of how students applied multiplicative reasoning in composing mathematics problems. These results are couched in a discussion of how the students solved the proportional reasoning tasks.

abstract: Industry, academia, and government have spent tremendous amounts of money over several decades trying to improve the mathematical abilities of students. They have hoped that improvements in students' abilities will have an impact on adults' mathematical abilities in an increasingly technology-based workplace. This study was conducted to begin checking for these impacts. It examined how nine adults in their workplace solved problems that purportedly entailed proportional reasoning and supporting rational number concepts (cognates). The research focused on four questions: a) in what ways do workers encounter and utilize the cognates while on the job; b) do workers engage cognate problems they encounter at work differently from similar cognate problems found in a textbook; c) what mathematical difficulties involving the cognates do workers experience while on the job, and; d) what tools, techniques, and social supports do workers use to augment or supplant their own abilities when confronted with difficulties involving the cognates. Noteworthy findings included: a) individual workers encountered cognate problems at a rate of nearly four times per hour; b) all of the workers engaged the cognates primarily via discourse with others and not by written or electronic means; c) generally, workers had difficulty with units and solving problems involving intensive ratios; d) many workers regularly used a novel form of guess & check to produce a loose estimate as an answer; and e) workers relied on the social structure of the store to mitigate the impact and defuse the responsibility for any errors they made. Based on the totality of the evidence, three hypotheses were discussed: a) the binomial aspect of a conjecture that stated employees were hired either with sufficient mathematical skills or with deficient skills was rejected; b) heuristics, tables, and stand-ins were maximally effective only if workers individually developed them after a need was recognized; and c) distributed cognition was rejected as an explanatory framework by arguing that the studied workers and their environment formed a system that was itself a heuristic on a grand scale. / Dissertation/Thesis / Doctoral Dissertation Curriculum and Instruction 2015

Doctor of Philosophy / Curriculum and Instruction Programs / Jennifer M. Bay-Williams / This study examined end-of-the-year seventh grade students’ rational number knowledge using comparison tasks and rational number subconstruct tasks. Comparison tasks included: comparing two decimals, comparing two fractions and comparing a fraction and a decimal. The subconstructs of rational number addressed in this research include: part-whole, measure, quotient, operator, and ratio. Between eighty-six and one-hundred-one students were assessed using a written instrument divided into three sections. Nine students were interviewed following the written instrument to probe for further understanding. Students were classified by error patterns using decimal comparison tasks. Students were initially to be classified into four groups according to the error pattern: whole number rule (WNR), zero rule (ZR), fraction rule (FR) or apparent expert (AE). However, two new patterns emerged: ignore zero rule (IZR) and money rule (MR). Students’ knowledge of the subconstructs of rational numbers was analyzed for the students as a whole, but also analyzed by classification to look for patterns within small groups of students and by individual students to create a thick, rich description of what students know about rational numbers. Students classified as WNR struggled across almost all of the tasks. ZR students performed in many ways similar to WNR but in other ways performed better. FR and MR students had more success across all tasks compared to WNR and ZR. On average apparent experts performed significantly better than those students classified by errors. However, further analysis revealed hidden misconceptions and deficiencies for a number of apparent experts. Results point to the need to make teachers more aware of the misconceptions and deficiencies because in many ways errors reflect the school experiences of students.

This work was developed from the preparation, implementation and analysis of a didactical sequence aimed to promoting the learning of concept of rational number by students in the sixth year of elementary school. We used the concept of zone of proximal development by Vygotsky and the treatment and conversion concepts developed by Duval. It is believed, in accordance with Duval, that the concept can only occur when the student is able do the treatments and the conversions of mathematical objects and, in accordance to Vygotsky, that the process of teaching and learning should be geared to the needs of individuals. This research is theoretically and methodologically basad the Didactic Engineering, methodology aimed to studying the work in the classroom by internal validation, that is, comparing what the student knew before having contact with an educational tool to learn what he achieved after the completion of the work. The didactical sequence proposed could provide students with the appropriation of the concept of rational number, that is, they managed to make the treatments and conversions with the following forms of representation of rational numbers: natural language, decimal, fractional and figural. This form, assisting them in performing daily activities that involve on mathematical object. / Este trabalho consiste no desenvolvimento, na aplicação e na análise de uma sequência didática destinada à promoção da apropriação do conceito de número racional por alunos do sexto ano do Ensino Fundamental. Foram utilizados o conceito de zona de desenvolvimento proximal de Vygotsky e os conceitos de tratamento e conversão desenvolvidos por Duval. Acredita-se, conforme Duval, que a conceituação só pode ocorrer quando o aluno é capaz de realizar os tratamentos e as conversões dos objetos matemáticos e, segundo Vygotsky, que o processo de ensino e aprendizagem deve ser voltado para as necessidades dos sujeitos. Essa pesquisa tem como fundamento teórico-metodológico a Engenharia Didática, uma metodologia que busca estudar os trabalhos desenvolvidos em sala de aula por meio de um processo de validação interno, isto é, confrontando aquilo que o aluno sabia antes de ter contato com o instrumento didático com aquilo que ele conseguiu compreender após a realização do trabalho. A sequência didática proposta pode propiciar aos alunos a apropriação do conceito de número racional, isto é, eles foram capazes de realizar os tratamentos e as conversões com as seguintes formas de representação do número racional: em língua natural, decimal, figural e fracionária. Fato que pode auxiliar os alunos na realização de atividades cotidianas que envolvam este objeto matemático.

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L’objet de cette thèse est l’étude de la propagation de la 2-birationalité pour les 2-extensions de corps de nombres. Le problème étudié se présente comme suit : étant donnés un corps 2-rationnel totalement réel K, une extension quadratique totalement imaginaire L de K, et une 2-extension totalement réelle de K de K, à quelles conditions la 2-birationalité du compositum L = KL se lit-elle sur L ? La thèse se structure en trois parties : l’étude du cas absolument quadratique d’abord, le cas relativement quadratique ensuite ; le cas général enfin. Le résultat principal de la thèse résout complètement le problème posé en toute généralité. En fin de thèse, diverses illustrations numériques sont proposées à l’aide du PARI, ainsi qu’une étude des tours d’extensions 2-birationnelles. / This thesis deals with the propagation of 2-birationality for 2-extensions of numbers fields. More precisely, le t K be a 2-rational totally real number field, L a CM quadratic extension of K, and let K be a totally real 2-extension of K. Under which conditions can one read the 2-birationaltiy of the compositum L = LK from L ? This work is divided into three parts : we first study the absolute quadratic case, then the relatively quadratic case, then finally the general case. The thesis’s main result solves the whole problem. We also illustrate the result with various numeric examples, obtained with PARI and a focus at the end on 2-birational extensions’ towers.