Development of fraction number line estimation was assessed longitudinally over 5 time points between 4th and 6th grades. Although students showed positive linear growth overall, latent class growth analyses revealed 3 distinct growth trajectory classes: Students who were highly accurate from the start and became even more accurate (n = 154); students who started inaccurate but showed steep growth (n = 121); and students who started inaccurate and showed minimal growth (n = 197). Younger and minimal growth students typically estimated both proper and improper fractions as being less than 1, failing to base estimates on the relation between the numerator and denominator. Class membership was highly predictive of performance on a statewide-standardized mathematics test as well as on a general fraction knowledge measure at the end of 6th grade, even after controlling for mathematic-specific abilities, domain-general cognitive abilities, and demographic variables. Multiplication fluency, classroom attention, and whole number line estimation acuity at the start of the study predicted class membership. The findings reveal that fraction magnitude understanding is central to mathematical development. (PsycINFO Database Record
The goal of the present article is to synthesize findings to date from the Delaware Longitudinal Study of Fraction Learning. The study followed a large cohort of children ( N = 536) between Grades 3 and 6. The findings showed that many students, especially those with diagnosed learning disabilities, made minimal growth in fraction knowledge and that some showed only a basic grasp of the meaning of a fraction even after several years of instruction. Children with low growth in fraction knowledge during the intermediate grades were much more likely to fail to meet state standards on a broad mathematics measure at the end of Grade 6. Although a range of general and mathematics-specific competencies predicted fraction outcomes, the ability to estimate numerical magnitudes on a number line was a uniquely important marker of fraction success. Many children with mathematics difficulties have deep-seated problems related to whole number magnitude representations that are complicated by the introduction of fractions into the curriculum. Implications for helping students with mathematics difficulties are discussed.
A COVID-19 é uma síndrome respiratória aguda grave (SRAG) infecciosa, causada por coronavírus. A doença tem alta transmissibilidade e ocasiona sintomas leves a graves, gerando elevada demanda por cuidados intensivos e milhares de óbitos. Em março de 2020, a COVID-19 foi caracterizada como pandemia e já soma mais de 5 milhões de casos e 300 mil óbitos pelo mundo. A história natural da doença ainda não é bem estabelecida, dificultando a elaboração de protocolos clínicos eficazes e medidas de prevenção. Apesar disso, pode-se afirmar que é uma doença de abordagem sistêmica, já que há evidências de complicações agudas e crônicas, além de efeitos catastróficos na saúde mental da população. Destaca-se então a necessidade de uma metodologia que capte de forma mais efetiva os efeitos da COVID-19, considerando aspectos como sua gravidade, duração e potencial de gerar complicações crônicas que aumentarão as demandas no Sistema Único de Saúde (SUS). Nesse sentido, é de extrema utilidade o indicador DALY, ou anos de vida perdidos por morte prematura ajustados por incapacidade (DALY), que agrega a (1) mortalidade - estimativa dos anos de vida perdidos (YLL) e (2) morbidade - estimativa dos anos vividos com incapacidade (YLD). Este artigo discute a relevância e as dificuldades de estudar a carga da COVID-19 e de suas complicações, no contexto brasileiro, ressaltando a importância de caracterizar a história natural da doença e estimar indicadores como o YLD, que considerem a alta carga de morbidade no planejamento de estratégias para lidar com as consequências da COVID-19 pós-pandemia. Discute-se também os desafios futuros para o enfrentamento da doença no SUS e reflexões sobre o cálculo do DALY.
The effectiveness of an experimental middle school fraction intervention was evaluated. The intervention was centered on the number line and incorporated key principles from the science of learning. Sixth graders (N = 51) who struggled with fraction concepts were randomly assigned at the student level to the experimental intervention (n = 28) or to a business-as-usual control who received their school’s intervention (n = 23). The experimental intervention occurred over 6 weeks (27 lessons). Fraction number line estimation, magnitude comparisons, concepts, and arithmetic were assessed at pretest, posttest, and delayed posttest. The experimental group demonstrated significantly more learning than the control group from pretest to posttest, with meaningful effect sizes on measures of fraction concepts (g = 1.09), number line estimation as measured by percent absolute error (g = −.85), and magnitude comparisons (g = .82). These improvements held at delayed posttest 7 weeks later. Exploratory analyses showed a significant interaction between classroom attentive behavior and intervention group on fraction concepts at posttest, suggesting a buffering effect of the experimental intervention on the normally negative impact of low attentive behavior on learning. A number line–centered approach to teaching fractions that also incorporates research-based learning strategies helps struggling learners to make durable gains in their conceptual understanding of fractions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.