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O Pensamento Computacional (PC) pode ser visto como uma metodologia para solucionar problemas das mais diversas áreas com fundamentação em conceitos da Ciência da Computação. A Base Nacional Comum Curricular já faz referências a essa metodologia e habilidades relacionadas, porém de forma pontual e, principalmente, relacionadas à unidade temática Álgebra da Matemática. Neste trabalho, são apresentadas habilidades que relacionam diferentes áreas temáticas da Matemática do primeiro ano do Ensino Fundamental e alguns conceitos do PC com o objetivo de ilustrar a abrangência e a viabilidade da integração desta metodologia no currículo desde os primeiros anos do ensino.

Este trabalho tem por objetivo apresentar a análise de como duas coleções de livros didáticos, aprovadas pelo PNLD 2020, abordam as habilidades propostas pela BNCC-Matemática relacionadas ao Pensamento Computacional, em particular, na unidade temática “Álgebra”. Para tanto, buscou-se fundamentação teórica nas propostas curriculares e nas pesquisas que problematizam relações entre os pensamentos Matemático e Computacional. Adotou-se pressupostos da pesquisa qualitativa. Os resultados indicam que o estudo de algoritmos, representados por fluxogramas, ainda é muito incipiente, precisando ser melhor trabalhados, principalmente, em relação a simbologia e a relação com conteúdos/conceitos matemáticos, em especial, identificação de padrões.

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Este texto tem por objetivo apresentar uma pesquisa que analisou de que modo as propostas para o estudo de Equações Diferenciais Ordinárias (EDO), presentes em livros-texto, podem contribuir no trabalho de professores de Matemática ao selecionarem situações-problema envolvendo o conceito de função. Os pressupostos teóricos para construção desta pesquisa referem-se a Abordagem Qualitativa e a Análise de Modelos Matemáticos. Optou-se por uma pesquisa qualitativa com a produção e análise dos dados seguindo pressupostos da Análise de Conteúdo. A fonte de produção de dados foi a análise de dois livros-texto de Equações Diferenciais mais citados por cursos brasileiros de Licenciatura em Matemática. A análise dos dados permitiu concluir que ambos os livros apresentam modelos matemáticos para estudar EDO, sendo as funções mais exploradas as exponenciais, quadráticas e trigonométricas, em detrimento da função logarítmica, não abordada nos capítulos analisados. Quanto a abordagem qualitativa, verificou-se que é utilizada, também, em ambos os livros, porém de forma limitada em um deles, pois não explora as potencialidades do campo de direções.

Atmospheric downward longwave radiation flux (L↓) is a variable that directly influences the surface net radiation and consequently, weather and climatic conditions. Measurements of L↓ are scarce, and the use of classical models depending on some atmospheric variables may be an alternative. In this paper, we analyzed L↓ measured over the Brazilian Pampa biome. This region is located in a humid subtropical climate zone and characterized by well defined seasons and well distributed precipitation. Furthermore, we evaluated the performance of the eleven classical L↓ models for clear sky with one-year experimental data collected in the Santa Maria experimental site (SMA) over native vegetation and high relative humidity throughout the year. Most of the L↓ estimations, using the original coefficients, underestimated the experimental data. We performed the local calibration of the L↓ equations coefficients over an annual period and separated them into different sky cover classifications: clear sky, partly cloudy sky, and cloudy sky. The calibrations decreased the errors, especially in cloudy sky classification. We also proposed the joint calibration between the clear sky emissivity equations and cloud sky correction function to reduce errors and evaluate different sky classifications. The results found after these calibrations presented better statistical indexes. Additionally, we presented a new empirical model to estimate L↓ based on multiple regression analysis using water vapor pressure and air temperature. The new equation well represents partial and cloudy sky, even without including the cloud cover parameterization, and was validated with the following five years in SMA and two years in the Cachoeira do Sul experimental site (CAS). The new equation proposed herein presents a root mean square error ranging from 13 to 21 Wm−2 and correlation coefficient from 0.68 to 0.83 for different sky cover classifications. Therefore, we recommend using the novel equation to calculate L↓ over the Pampa biome under these specific climatic conditions.

Knowledge of soil thermal properties (diffusivity (k) and conductivity (λ)) is important to understand the soil–plant–atmosphere interaction related to the physical and biological processes associated with energy transfer and greenhouse gas exchanges. The incorporation of all the physical processes that occur in the energy transfer in the soil is a challenge in order to correctly estimate soil thermal properties. In this work, experimental measurements of soil temperature and soil heat flux obtained in a silty clay loam soil covered by native grassland located in the Brazilian Pampa biome were used to estimate soil thermal properties using different methods including the influence of the soil water content at different soil depths in heat transfer processes. The λ was estimated using the numerical solution of the Fourier equation by the Gradient and Modified Gradient methods. For the surface layer, the results for both models show large variability in daily values, but with similar values for the annual mean. For λ at different soil depths, both models showed an increase of approximately 50% in the λ value in the deeper layers compared to the surface layer, increasing with depth in this soil type. The k was estimated using analytical and numerical methods. The analytical methods showed a higher variability and overestimated the values of the numerical models from 15% to 35%. The numerical models included a term related to the soil water content. However, the results showed a decrease in the mean value of k by only 2%. The relationship between thermal properties and soil water content was verified using different empirical models. The best results for thermal conductivity were obtained using water content in the surface layer (R2 > 0.5). The cubic model presented the best results for estimating the thermal diffusivity (R2 = 0.70). The analyses carried out provide knowledge for when estimating soil thermal properties using different methods and an experimental dataset of soil temperature, heat flux and water content, at different soil depths, for a representative soil type of the Brazilian Pampa biome.

This study aims to analyze how textbook collections, approved by the Programa Nacional do Livro Didático, address the algorithms construction for solving geometric problems. This is a qualitative research, based on assumptions of Content Analysis. The analysis was based on situations related to Computational Thinking and geometric concepts, contained in eight collections of Elementary School textbooks, showing skills of the Base Nacional Comum Curricular. We found that of the skills associated with Computational Thinking, EF06MA23 contained the largest number of situations involving algorithms construction. As for the representations proposed for the organization of the algorithm, approximately 46% of the mobilizations carried out were approached by exploring natural language and 41% in the flowchart/schema representation. Furthermore, only 9 situations explore different types of representation in the algorithm construction. The algorithm represented in programming language was identified in only two collections, which suggest the use of visual programming environments/software.