It has been stated that a criterion of a threshold concept is that it is troublesome or difficult to understand. However, not all difficult concepts are also threshold concepts. This article explores this difference through the context of students' difficulties in learning prosthetics and two models of describing threshold concepts. Students and…

Multiplication and division are vital topics in upper level elementary school. A teacher's pedagogical content knowledge (PCK) influences both instruction and students' learning. However, there is currently little research examining teachers' PCK within this domain, particularly regarding professional education of future teachers. To help address…

This mixed methods action research study examined the implementation process and impact of a 9-week Number Talk intervention to build number sense in kindergarten students. Fifty-eight kindergarten students engaged in daily Number Talk lessons for 9 weeks. Qualitative data were collected to evaluate the strengths and challenges of the…

The main purpose of this study is to develop a conceptual understanding of the irrational number of the square root of 2 ([square root]2 ). Participants in the study were 20 ninth-grade male students. Activity Theory was used as a framework to show the development of the conceptual understanding. Since this study was conducted during the COVID-19…

Community college developmental math students (N = 657) from three math levels were asked to place five whole numbers on a line that had only endpoints 0 and 20 marked. How the students placed the numbers revealed the same three stages of behavior that Steffe and Cobb (1988) documented in determining young children's number sense. 23% of the…

A web-based two-tier test (WTTT-NS) which combined the advantages of traditional written tests and interviews in assessing number sense was developed and applied to assess students' answers and reasons for the questions. In addition, students' major misconceptions can be detected. A total of 1,248 sixth graders in Taiwan were selected to…

Pupils often find the concepts of heat and temperature difficult to understand and differentiate. The authors believe that an image-to-writing approach can help pupils learn these two abstract concepts -- an approach that uses a series of guided enquiry activities involving heat and temperature. The basic premise is that pupils produce images to…

The aim of this study is to investigate Danish pre-service teachers' (PSTs) mathematical and didactical knowledge of operations with rational numbers. This knowledge is studied through their collaborative activities to certain tasks related to the teaching of operations with rational numbers. An explicit model of the teachers' mathematical and…

Behavioral studies have reported interactions between number processing and spatial attention, suggesting that number processing involves shifting attention along a mental continuum on which numbers are represented in ascending order. However, direct evidence for attention shifts remains scarce, the respective contribution of the horizontal and…

Background: Teaching using manipulatives is emphasised, especially in the early grades, to help learners conceptualise operations on whole numbers. Therefore, teachers' competencies in using manipulatives is the key in helping learners master these basic operation skills. Aim: Drawing from the literature on using manipulatives to improve learners'…

The metaphor of the mental number line accounts for numerous empirical effects of spatial-numerical associations. In the present study, we aimed at investigating directional spatial-numerical associations reflected by SNARC-like digit-direction and sign-direction congruency effects as well as the sign-digit compatibility effect when 6th graders…

It has been reported that approximate number sense (ANS) task performance is impaired in individuals with Williams syndrome (WS) and Down syndrome (DS). Research with infants has suggested this impairment is caused by sticky fixation in WS and sustained attention deficits for those with DS. This study examined looking patterns of older children…

The author seeks to use the limited contact time they have with students to engage them not only in academic pursuits but also in a discussion of the divine mission of humans. Since this can be difficult to meaningfully do in a math class, the author is continually searching for meaningful, engaging points of contact between mathematics and…

Children and adults often have difficulties comparing decimal magnitudes. Although individuals attempt to reconcile decimals with prior whole-number and fraction knowledge, conceptual and procedural differences between decimals and prior knowledge of whole numbers and fractions can lead to incorrect strategies. The dynamic strategy choice account…

This study explores the effects of number structure characteristics on student thinking in solving missing-value proportion problems. Prior research has documented that the presence of an integer ratio is beneficial, particularly if the integer relationship is within the same measure space. Less information on student performance is available,…