Os limites e as possibilidades de uma sequência didática: o conceito de proporcionalidade e a aprendizagem de alunos do 5º ano do Ensino Fundamental

This study aimed to analyze the limits and possibilities of a didactic sequence, addressing the concept of proportionality in the learning of students in 5th year of elementary school. From the results of the Diagnostic Assessment Initial applied to students in a class of 5th grade of elementary school, we selected eight (8) students who participated in the constituent activities of that instructional sequence. For the development of this sequence were used theoretical elements of Genetic Epistemology (Piaget, 1990), the theory of fields of Conceptual Vergnaud (1996) and the definition of instructional sequence proposed by Zabala (1998). Finally, after 20 days of application of these activities, we applied the Diagnostic Assessment Final aimed at investigating which concepts related to proportionality were built by the participating students. By analyzing the collected data, it can be concluded the following about the possibilities of teaching sequence: 1) students who, in Diagnostica Home Assessment used the multiplication algorithm, but also did not indicate the comparison between quantities are now performing; 2) students who, in the Diagnostic Assessment Initial, used the addition algorithm, now gradually are using the multiplication algorithm; 3)students who, in the Diagnostic Assessment Initial, could not solve problems involving the idea of proportionality, are now resolving, however, still use, in large part, the addition operation as a strategy for this proportional thinking. Now, in relation to the limits of the sequence noted: 1)time sufficient to propose a higher number of problem conditions to be carried by students who may have been a trigger of construction have not through the proportional multiplication;2)the distant proposition situations of assimilation schemes (interpretation) of the students, which may have caused certain imbalance in them, preventing them from thinking about the problem situation;3)the rapid passage of...

Survey assessment of parental perceptions regarding head lice

Background Head lice constitute a problem in children. Each year, numerous cases of pediculosis occur worldwide. Little work has been performed to evaluate the understanding, opinions, and actions of populations regarding head lice. These areas are important as they enable clinicians and educators to alert parents on how to avoid treatments that are innocuous or of high risk to patients.Methods A cross-sectional study was performed by interviewing the heads of households of 100 randomly chosen residences within the study area.Results The results obtained showed that 13% were infested during the first week of the survey, and 86% in the 24 weeks prior to the study. The number of positive cases increased with increasing resident number, and decreased in families with parents with a higher educational level. Itching was the principal clinical manifestation and caused sleep compromise in 65% of respondents. Innocuous and unhealthy practices to combat infestation, such as the use of inflammables and home insecticides, were common.Conclusion The results showed that certain beliefs generated worry and confusion in parents, who blamed head lice as the cause of various health problems which were not due to this insect.