Contextualization: teaching estimation to grade five and six learners using maize crop

A journal article on primary mathematics education in Zimbabwe.Estimation is one of the motivating concepts in mathematics especially if one gets accurate or close to accurate answers. In this paper we look at how 26 primary school learners in Grade 5 and 6 in Masvingo district, Zimbabwe, learnt this mathematical concept practically using maize during their holiday lessons. They measured the length and circumference of maize cobs at the base, and counted the number of seeds. After that they then filled a bucket. The idea was to find out how many maize cobs it would take to fill a 20 kilogramme bucket, a 50 kilogramme sack, and subsequently a tonne. After that the learners went on to estimate the three features of maize cobs (length, circumference at the base and the number of seeds). The entire exercise was mainly based on estimating the number that can Jill a bucket. After the study, the level of application of the concept was astounding as they went on to estimate the yields in their fields where the results were very close

Time-consistent investment-proportional reinsurance strategy under a jump-diffusion model

In this paper, we formulate a mean-variance portfolio selection problem of an insurer who manages her underlying risk by purchasing proportional reinsurance and investing in a financial market consisting of a bank account and a risky asset following a jump-diffusion dynamics with random parameters. We then obtain a time-consistent equilibrium strategy via a flow of Backward Stochastic Differential Equations. Finally, we apply our results to a mean-reverting Levy-Ornstein-Uhlenbeck process and obtain closed form solutions

Up-side-down (Dyakodo): teaching and learning method of mathematics

A research paper on an innovative and effective method of teaching Mathematics in Zimbabwe.The paper presents results ofa research on one method ofteaching and learning mathematics based on observations on and experiences of 35 Form One learners and 6 teachers ataZengeza school in Chitungwiza, about 2 J kilometers south ofHarare. The pass rate rose from 7% to an astonishing 61% in a space of a 20 school days. Cipra (1988), Steen (1988), and White & Mitchelmore (1996) have raised much concern in the failure by teachers to develop a conceptual understanding of mathematics topics because of the rote, manipulative learning that takes place in classrooms at introductory secondary school levels. Lithner (2003, 2004) also remarks that most exercises in mathematics textbooks may be solved by mathematically superficial strategies, often with>.:. ssentially considering the core mathematics of the book section in question. It is along these lines that the up-side-down (dyakodo) teaching and learning method in mathematics has been found to be an effective method of teaching mathematics for understanding. The up-side-down (dyakodo) teaching and learning method allows learners to do lessons at home and then home-work in class in order to integrate important ’real-world' everyday life activities into the school activities

Análisis de la frecuencia y severidad de hipomineralización molar incisiva en niños de hasta 8 años

Molar Incisor hypomineralization (MIH) describes a clinical picture of hypomineralization of systematic and genetic origin affecting one or more first permanent molars and incisors. Reduction in enamel’s concentration characterizes affected teeth, creating white, yellow or brown asymmetric opacities of different extensions and severities. Inadequacy in enamel’s mineralization in (MIH) leads to weaker enamel, becoming thin and leaving the dentin complex exposed. Consequently, higher sensibility and susceptibility to cavities in molars and hypomineralized incisors is aroused. Higher incidence of MIH in the last decade reveals the necessity of further research, in order to clarify etiological factors and improve restorations’ durability on the affected teeth. The purpose of the following research paper, is to analyze the diagnosis, prevalence, frequency, hypothetical etiological factors, and features of hypomineralized enamel in molar incisor hypomineralization. A sequential management approach is suggested.La Hipomineralización Molar Incisiva es una anomalía del desarrollo dentario de etiología desconocida, asociada a alteraciones de origen sistémico y genético que afectan de uno a cuatro primeros molares permanentes e incisivos. Clínicamente los dientes afectados se caracterizan por la disminución en la concentración del esmalte, lo que provoca opacidades asimétricas de color blanco, amarillo o marrón de diferentes extensiones y severidades. La deficiencia en la mineralización del esmalte en MIH, da como resultado un esmalte debilitado, el cual es delgado y expone al complejo dentinario. Esto causa mayor sensibilidad y susceptibilidad a caries en las molares e incisivos hipomineralizados. La alta prevalencia de MIH en la última década evidencia la necesidad de una investigación para aclarar los factores etiológicos y desarrollar un mejor tratamiento preventivo y rehabilitador de los dientes afectados. El propósito de este trabajo es analizar el diagnóstico, la prevalencia, la frecuencia, los factores etiológicos hipotéticos, y las características del esmalte hipomineralizada en MIH y presentar un protocolo ideal de manejo para la patología

Sustainability and the digital age: exploring sustainable production and consumption behaviors

The digital age had a profound impact on communications and businesses,exacerbating the worldwide rate of consumption and production that depletes Earth’s natural resources. This paper explores how the digital age relates to businesses' and consumers' sustainable practices. Results from an online questionnaire and a company interview, support that companies have adapted to the digital world and to the increasingly demanding and conscientious consumers. Society is making progress, nevertheless, although individuals are more aware of their consumption's negative impact on the environment and are changing the way they dispose of and use products, their purchase habits are still mainly unaltered