Additional Problems Research Articles

Neural evidence for procedural automatization during cognitive development: Intraparietal response to changes in very-small addition problem-size increases with age

Cognitive development is often thought to depend on qualitative changes in problem-solving strategies, with early developing algorithmic procedures (e.g., counting when adding numbers) considered being replaced by retrieval of associations (e.g., between operands and answers of addition problems) in adults. However, algorithmic procedures might also become automatized with practice. In a large cross-sectional fMRI study from age 8 to adulthood (n = 128), we evaluate this hypothesis by measuring neural changes associated with age-related reductions in a behavioral hallmark of mental addition, the problem-size effect (an increase in solving time as problem sum increases). We found that age-related decreases in problem-size effect were paralleled by age-related increases of activity in a region of the intraparietal sulcus that already supported the problem-size effect in 8- to 9-year-olds, at an age the effect is at least partly due to explicit counting. This developmental effect, which was also observed in the basal ganglia and prefrontal cortex, was restricted to problems with operands ≤ 4. These findings are consistent with a model positing that very-small arithmetic problems–and not larger problems–might rely on an automatization of counting procedures rather than a shift towards retrieval, and suggest a neural automatization of procedural knowledge during cognitive development.

Simultaneous removal of multi-nuclide (Sr2+, Co2+, Cs+, and I-) from aquatic environments using a hydrate-based water purification process

This study investigates the removal characteristics of a hydrate-based water purification process used to remove the major radionuclides monitored in nuclear accident areas. The effect of the coexistence of salt ions on the removal of radioactive materials is also evaluated. Previous studies have found existing processes such as ion exchange and membrane separation to be reliable methods for radionuclide removal from contaminated water. However, these processes cannot remove all contaminants at once and cause additional environmental problems by generating secondary wastes. In a previous study, we observed that water purification by the gas hydrate process could simultaneously remove various ions from seawater and hypersaline water in a single step without pre- or post-treatment. Therefore, the removal characteristics of Sr2+, Co2+, Cs+, and I- radionuclides are evaluated in only one context: the hydrate-based water purification process. More than 85% of the total ions were simultaneously removed regardless of the presence or absence of coexisting ions, and the time required for the removal process was about 70 min. In addition, it was observed that most of the contaminant ions were attached to hydrate crystal surfaces. Therefore, an efficient purification process is proposed that includes a hydrate crystal exterior partial dissolution step.

Australian children with cerebral visual impairment: using what we know now to improve future approaches

ABSTRACT Purpose Little has been reported on Australian children with Cerebral Vision Impairment (CVI). This paper aims to present the outcome of an audit focussed on children with the primary diagnosis of CVI, using findings from the Australian Childhood Vision Impairment Register (ACVIR). Methods Records on 132 children (49% girls, 51% boys) from ACVIR data gathered from both the child’s parent/guardian and their eye health professional were reviewed. The child’s demographics, level of vision impairment, birth history, diagnostic journey, secondary ocular diagnoses, comorbidities and low vision support were analyzed. Several correlations were investigated using a Kendall’s tau-b analysis including the relationship between vision and age of diagnosis; level of vision and developmental delay; and age of suspicion of visual impairment and age of diagnosis. Results The most common level of visual impairment was blindness (39%), and most children were suspected and diagnosed of visual impairment in the first 6 months of life. The majority of children were born full term (72%), weighing >2000gms (84%). Nearly half of the cohort of children (48%) had a secondary ocular diagnosis with 44% having nystagmus. The majority of children (80%) had additional health problems, and 85% of children had additional disabilities, with 79% having developmental delay. Conclusion While the findings of this audit cannot be generalized to a wider population of Australian children with CVI, the outcome encourages continued discussion on CVI, to explore comprehensive assessment approaches which facilitate timely and accurate diagnosis.

LOCALLY CHARACTERISED REPETITIVE ILLEGAL LANDFILLS CLASSIFICATION

Illegal dumping of waste material is present in almost all local communities in Bosnia and Herzegovina, including in the areas of urban and rural local communities of the City of Tuzla. Uncontrolled waste dumping at the landfields, as the illegal dumping, are created by dumping different types of waste material in areas that are not intended for waste material disposal. These are areas that are usually next to roads with less traffic, or in the immediate vicinity of roads where access is possible for motor vehicles with a lower load capacity. Illegal landfills have a direct negative impact on the living environment from several aspects. Primarily, watercourses and soil are polluted, the ambient space is disturbed, and by attracting animals, there is the possibility of infections that are dangerous for the population. Waste materials in illegal landfills are often deliberately set on fire, which causes additional problems of air pollution with smoke and gases resulting from combustion, as well as the possibility of fire outbreaks, especially in forest areas. In the current practice, illegal waste landfills did not have scientific and professional interest because they are often of a temporary nature and were not considered interesting from the aspect of the scientific approach to defining landfills by different classifications. This paper defines the classification of illegal landfills in the spheres of data processing possibilities of interest for the treatment of illegal waste landfills, and the experimental definition of the classification was confirmed on the example of the recording and analysis of illegal waste landfills in the local community of Kiseljak, City of Tuzla in the phase of implementing the project „Inclusive development of Kiseljak community for improvement of social and economic aspect of citizens, emphasizing Roma population“, finance by Foundation of Tuzla community, Tuzla. The basis of the classification is made up of repetitive local waste landfills, while permanent regional waste landfills are not the subject of research and classification since there are already known classifications for permanent waste material landfills. Consent for the publication of the paper was given by the Tuzla Community Foundation, which financed the referral research within the project "Inclusive development of the Kiseljak community, for the improvement of the social and economic aspects of the citizens' life, especially the Roma", implemented by the Tuzla Community Foundation in partnership and financial support of the Freudenberg Foundation and the German Federal Ministry for External Development (BMZ).

ANALISIS TANGGUNG JAWAB PENGELOLA PARKIR TERHADAP KEHILANGAN BARANG MAHASISWA UIN JAKARTA

This research aims to determine the responsibility of parking managers for the loss of goods in parking areas considering that the increasing number of motorized vehicles in Indonesia creates additional problems in the required parking management system. Parking managers are responsible for the security of vehicles and goods in the parking area based on Article 1706 and Article 1714 of the Civil Code (KUHPerdata). Parking management is a matter of public law, but if a relationship exists between the parking manager and consumers, then the concept of certainty and the existence of rights and obligations will give rise to concepts in private law. In 2019, the National Consumer Protection Agency (BPKN) issued Circular Number 1 of 2019 concerning Consumer Protection regarding the Responsibilities of Parking Managers which emphasized that parking managers are responsible for lost goods that occur in the parking area. The parking manager can be held liable by the injured party on the basis of a breach of contract (negligence) in the goods custody agreement between the parking lot manager and the motorbike owner. In the case of lost items from UIN Jakarta students, the parking lot manager can be held responsible for the losses experienced by the student. Parking lot managers also have a moral responsibility to maintain the safety of goods entrusted to them by consumers. Efforts such as strict supervision, installing CCTV cameras, and providing experienced and trained parking attendants must be taken to prevent loss of goods from consumers.

An exploration of grade 2 learners’ experiences in solving addition and subtraction word problems

Mathematics has always been a major part of school curricula in most countries. It provides a variety of useful tools that help students to solve problems that they encounter in everyday life. Mathematical tools are considered powerful, as long as one knows how to employ them across a range of suitable situations. However, selecting and using these tools appropriately appear to be challenging for many students. Because of this, word problems have been included in mathematics education to offer practice for students in applying mathematical skills effectively in various problem situations confronted in everyday circumstances. In addition, there is limited research about how learners in the foundation phase (Grades 1-3) solve addition and subtraction word problems. A relatively recent review of South African studies on mathematics education has revealed a paucity of research at the primary school level. This study therefore seeks to explore grade 2 learners’ experiences in solving addition and subtraction word problems. A qualitative research was conducted to describe grade 2 learners experience whilst solving addition and subtraction problems. Only 6 learners in grade 2 were selected to participate in this study. Learners demonstrated a strong preference for paper and pencil methods as well as the standard algorithm, when solving problems in word format. However, little evidence exists within the study that any of the learners conceptually understood the algorithm. The use of base 10 blocks to model the partial sums and partial differences algorithms would help most of the learners to develop a conceptual understanding of addition and subtraction of word problems in mathematics.

Spontaneous emission in the supercritical QED: What is wrong and what is possible

Spontaneous positron emission, caused by the supercritical Coulomb source with charge [Formula: see text] and size [Formula: see text], is explored in essentially nonperturbative approach with emphasis on the VP-energy [Formula: see text] a , considered as a function of the Coulomb source parameters [Formula: see text] and [Formula: see text]. The specific contribution to [Formula: see text], which appears in the supercritical case due to direct Coulomb interaction between VP-charge densities [Formula: see text], is outlined and studied in detail. It is shown that after first levels diving into the lower continuum, this contribution to [Formula: see text], being properly renormalized, turns out to be negative in contrast to the classical electrostatics and so could play an important role in spontaneous emission, especially for [Formula: see text] just above the first [Formula: see text]. The additional problems of spontaneous emission, caused by the lepton number conservation, are also discussed.

Health Problems Related to Presenteeism Among Japanese Employees.

This study identified primary health problems related to presenteeism stratified by sex. A cross-sectional study was conducted to analyze the relationship between 26 health problems and presenteeism using data from health-related data and World Health Organization Health and Work Performance Questionnaire among 12,526 employees in Japan. Sex-stratified multiple regression analyses showed that presenteeism was associated with nine health problems in both sexes, depressive symptoms, followed by lack of appetite, insufficient sleep, heart palpitations, or shortness of breath demonstrated the strongest relationship. Men had five additional health problems associated with presenteeism; furthermore, the relationships of those were stronger than women. The primary health problems related to presenteeism were depressive symptoms and indefinite complaints in both sexes. Men had more and stronger relationship between health problems and presenteeism than women.

Pengabdian kepada Masyarakat: Penyuluhan Pengetahuan Manajemen Stres Bagi Pelaku UMKM di Azalea Depok

<p><em>MSME actors and e</em><em>mployees at work often feel stressed either because of the work environment or the impact of problems brought from outside the work environment. Even more so when it is associated with the prolonged impact of the COVID-19 pandemic. This can further make employees anxious to continue working. Business conditions in this case also become a determining factor. In addition, internal and external problems experienced by employees can also be an additional factor in forming anxiety to continue working which in the long run can create stress at a certain level. These things were used as the background for the initial situation analysis as a detector of partner problems, namely employees working at Azalea's Micro, Small and Medium Enterprises (MSMEs) in </em><em>Depok</em><em>. The implementing team then determined the method of Community Service activities</em><em> </em><em>to be carried out, namely counseling. This PkM activity was held on March 8-9, 2023, face to face on the spot. During the material bidding process, activities went well and smoothly. Based on the results of the feedback obtained from the 32 participants who took part, the participants felt that this PkM activity provided additional knowledge for the participants, especially regarding stress management. In addition, the participants also felt that the topics raised and presented to the participants matched the participants' needs in recognizing stress to managing stress in the workplace. The participants also felt that the activities provided were sufficient in terms of implementation time. Furthermore, the participants hoped that other activities could be carried out in the future.</em></p>

'Low-value' clinical care ingeneral practice: a cross-sectional analysis oflow-value care inearly-career GPs' practice.

Nonevidence-based and 'low-value' clinical care and medical services are 'questionable' clinical activities that are more likely to cause harm than good or whose benefit is disproportionately low compared with their cost. This study sought to establish general practitioner (GP), patient, practice, and in-consultation associations of an index of key nonevidence-based or low-value 'questionable' clinical practices. The study was nested in the Registrar Clinical Encounters in Training study-an ongoing (from 2010) cohort study in which Australian GP registrars (specialist GP trainees) record details of their in-consultation clinical and educational practice 6-monthly. The outcome factor in analyses, performed on Registrar Clinical Encounters in Training data from 2010 to 2020, was the score on the QUestionable In-Training Clinical Activities Index (QUIT-CAI), which incorporates recommendations of the Australian Choosing Wisely campaign. A cross-sectional analysis used negative binomial regression (with the model including an offset for the number of times the registrar was at risk of performing a questionable activity) to establish associations of QUIT-CAI scores. A total of 3206 individual registrars (response rate 89.9%) recorded 406 812 problems/diagnoses where they were at risk of performing a questionable activity. Of these problems/diagnoses, 15 560 (3.8%) involved questionable activities being performed. In multivariable analyses, higher QUIT-CAI scores (more questionable activities) were significantly associated with earlier registrar training terms: incidence rate ratios (IRRs) of 0.91 [95% confidence interval (CI) 0.87, 0.95] and 0.85 (95% CI 0.80, 0.90) for Term 2 and Term 3, respectively, compared to Term 1. Other significant associations of higher scores included the patient being new to the registrar (IRR 1.27; 95% CI 1.12, 1.45), the patient being of non-English-speaking background (IRR 1.24; 95% CI 1.04, 1.47), the practice being in a higher socioeconomic area decile (IRR 1.01; 95% CI 1.00, 1.02), small practice size (IRR 1.05; 95% CI 1.00, 1.10), shorter consultation duration (IRR 0.99 per minute; 95% CI 0.99, 1.00), and fewer problems addressed in the consultation (IRR 0.84; 95% CI 0.79, 0.89) for each additional problem]. Senior registrars' clinical practice entailed less 'questionable' clinical actions than junior registrars' practice. The association of lower QUIT-CAI scores with a measure of greater continuity of care (the patient not being new to the registrar) suggests that continuity should be supported and facilitated during GP training (and in established GPs' practice).

The gradual removal of Hertz pressure from the surface of elastic half-space

Contact stress determination in non-stationary dynamic loading of elastic bodies is crucial for modelling structures at high speeds, but it presents mathematical challenges due to the time-dependent and often unknown contact area size and shape. The study aims to obtain an energy remainder estimation that forms waves during the contact interaction of elastic bodies, based on the exact solutions of non-stationary problems for an elastic half-space. For this purpose, the problem of the instantaneous loading half-space as an additional research problem was reconstructed using the Hankel transform concerning a radial coordinate and the Laplace transform concerning a time variable. The method of derivation of the displacements at an elastic half-space loaded (unloaded) gradually by Hertz's contact pressure has been proposed. Its availability made it possible to pass to the solution of the main problem – the problem of gradual loading of the half-space surface by Hertz pressure. The possibility of changing of the order of differentiation and integration operations in the obtained representation is substantiated based on the integrand properties. The cases when the speed of the indenter was constant when its motion was uniformly accelerated and when the motion corresponded to the law of the first quarter of the cosine period in the time were considered. It was concluded that the distribution of dynamic contact stresses is similar to the Hertz distribution. An estimation of the part of the energy spent on the formation of elastic waves was made for various laws of unloading. The practical significance of this study lies in its development of an effective method for calculating normal displacements on a loading area in dynamic contact interactions of elastic bodies, which can be valuable for modelling structures at high speeds

Fetal Third-Trimester Functional Cardiovascular Abnormalities and Neonatal Elevated Bilirubin Level.

The aim of the study was to analyze the neonatal outcomes of fetuses with diagnosed functional cardiovascular abnormalities, also considering the connection with neonatal hyperbilirubinemia. It was an observational study of 100 neonates who had fetal echocardiography examinations in the third trimester (mean gestational age during the last echocardiography was 34 ± 3 weeks and mean birth weight was 3550 g). There were two groups: A: normal heart anatomy + no functional anomalies; group B: normal heart anatomy + functional abnormalities. Hyperbilirubinemia was defined as a bilirubin level of >10 mg%. In group A, there were 72 cases and only 5 cases despite having normal heart anatomy and normal heart study that presented additional problems. In group B (28 cases), the prenatal functional findings included tricuspid regurgitation (TR) (15 cases, 53%), pericardial effusion (4 cases, 14%), myocardial hypertrophy (4 cases, 14%), cardiomegaly (2 cases, 7%), abnormal bidirectional blood flow across the foramen ovale (3 cases, 11%), aneurysm of atrial septum (2 case, 7%), abnormal E/A ratio for mitral and tricuspid valve (1 case, 3%), bright spot (3 case, 11%), abnormal Doppler flow in ductus arteriosus compared to aortic arch (difference >60 cm/s) (1 case, 3%), supraventricular tachycardia (SVT) (1 case), and mitral regurgitation (1 case, 3%). In group A (n = 72 cases), bilirubin levels of >10 mg/dL were observed in 8% of newborns. In group B (n = 28), bilirubin levels of > 10 m/dL were observed in 46% of cases and TR was present in group B in 53% of cases (15/28 cases). The difference between group A and B in terms of elevated bilirubin levels was statistically significant (p < 0.001). In the case of fetal normal heart anatomy and normal heart study, a good neonatal outcome may be expected. When fetal cardiovascular functional abnormalities in normal heart anatomy are detected, with special attention paid to tricuspid valve regurgitation, a neonatal elevated bilirubin level (mean 11 mg/dL, range 10-15 mg/dL) may be expected.

Analysis of Hidden Danger in Open Water Swimming Competition

Open-water swimming is an exercise that can enhance the athlete's physical fitness. Even though different swimmers enjoy swimming in open water competitions, there are still safety consequences with this competition, and people must plan this hidden danger before the event. Athletes swim in open-water swimming competitions in lakes, rivers, and oceans. The difference between open-water swimming and traditional swimming in swimming causes much more uncertainty. This essay will take place on all the potential threats in an open-water swimming event. The essay will be analyzing in different aspects of the open water competition. First is the natural landscape, temperature, water quality, and water flow. All of these will affect the athlete's performance. Second, the emergency that can happen to the athletes. For example, body issues, cramps, or low body temperature. Third, the athlete's body condition, some of the athletes might have some body issues that do not fit this event, which will cause some additional problems for the hosts of the swimming event. Fourth, the ethics issues in the sporting event. With a sport that includes a big group of people attending it, there will be some unethical moves to get a higher rank.

Cloud-based solutions used by hungarian SMEs and analysis of its effects

The wide range of technological innovations took place in the post-millennium period and later became widely available have fundamentally reshaped the relationship between ICT infrastructure and business in the life of for-profit organizations. This is particularly true for the so-called primary (value-creating) processes. These technologies that have fundamentally transformed the way business organizations operate are collectively referred to as "Industry 4.0" technologies. A significant group of these technologies are the cloud-based solutions. By using these solutions, the users can get benefits from the ICT infrastructure through a third-party service. These services can be applications made available on a specific online interface (SaaS), or various platform elements (PaaS, for example: application servers, virtual servers, etc.) or infrastructure elements such as leased computing capacity (IaaS). By using cloud-based solutions, the customer can avoid the investment needed to run the ICT infrastructure and the additional problems rooted by the operation of ICT-infrastructure. A questionnaire survey was carried out in early 2019, in which 498 respondents voluntarily participated. The survey investigated the deployment level of ICT infrastructure among SMEs in Hungary, its information security consequences and how the management of the for-profit organizations evaluate the contribution of ICT infrastructure to the success of their business. The use of different cloud-based solutions was also measured in the mentioned questionnaire. The paper presents the research results of the prevalence of use of different cloud solutions with similar studies in the region. Furthermore, it examines whether cloud solutions have individually detectable beneficial effects on business operations, and whether synergies can be identified when multiple cloud applications are used together. Based on the qualitative results of the research and their interpretation, a broader analysis has been offered.

Seven design principles for teaching complex socioscientific issues: the design of a complex systems agent-based disease epidemic model and the application of epistemic practices in high school biology

Historic challenges in the biological sciences, such as the spread of disease and climate change, have created an unprecedented need for humans to engage with scientific information to address societal problems. However, understanding these socioscientific issues (SSI) can be hard due to the difficulty of comprehending their complex structures and behaviors, the intentional propagation of misinformation, and an insufficient understanding of the epistemic practices that scientists use to develop relevant knowledge. Education researchers have highlighted additional problems in the way science is taught with a focus mainly on concepts rather than practices, competing curricular mandates, and professional development activities that do not provide usable knowledge. The research reported here follows more than a decade of work using agent-based computational models to support the comprehension and analysis of complex biological systems. Our recent work has aimed to build tools and strategies to support students in decision making about complex SSIs. In this paper, we discuss 7 design challenges and principles that underpin this recent focus. Specifically, we combine agent-based modeling with strategies to develop students’ epistemic performance in high school biology curricula. We then provide a detailed case study of how the 7 design principles were used to create a disease epidemic model and unit anchored in the biology topic of the nature of science. Our goal is to offer a comprehensive set of research-derived design principles that can bridge classroom experiences in biology to applications of SSIs.

How Distracting Events Influence Young and Older adults’ Arithmetic Performance?

ABSTRACT In this study, I investigated the role of distraction on arithmetic performance and whether this role changes with aging during adulthood. Young and older adults were asked to verify one-digit addition problems (Expt. 1) or to estimate the results of two-digit multiplication problems (Expt. 2). In both experiments, true and false simple problems (Expt. 1) or easier and harder complex problems (Expt. 2) were displayed superimposed or not on irrelevant, emotionally neutral pictures (e.g. mushrooms). In both simple and complex arithmetic, young and older adults obtained poorer arithmetic performance under distraction relative to no-distraction conditions. Most interesting, deleterious effects of irrelevant stimuli on arithmetic performance were larger in older than in young adults. Moreover, magnitude of distraction effects increased with longer solution latencies in young (but not in older) adults while solving complex arithmetic problems. These findings have important implications for furthering our understanding of the role of distraction on cognitive performance in general, and arithmetic performance in particular, as well as age-related differences in this role.

Correlative Imaging of Three-Dimensional Cell Culture on Opaque Bioscaffolds for Tissue Engineering Applications.

Three-dimensional (3D) tissue engineering (TE) is a prospective treatment that can be used to restore or replace damaged musculoskeletal tissues, such as articular cartilage. However, current challenges in TE include identifying materials that are biocompatible and have properties that closely match the mechanical properties and cellular microenvironment of the target tissue. Visualization and analysis of potential 3D porous scaffolds as well as the associated cell growth and proliferation characteristics present additional problems. This is particularly challenging for opaque scaffolds using standard optical imaging techniques. Here, we use graphene foam (GF) as a 3D porous biocompatible substrate, which is scalable, reproducible, and a suitable environment for ATDC5 cell growth and chondrogenic differentiation. ATDC5 cells are cultured, maintained, and stained with a combination of fluorophores and gold nanoparticles to enable correlative microscopic characterization techniques, which elucidate the effect of GF properties on cell behavior in a 3D environment. Most importantly, the staining protocol allows for direct imaging of cell growth and proliferation on opaque scaffolds using X-ray MicroCT, including imaging growth of cells within the hollow GF branches, which is not possible with standard fluorescence and electron microscopy techniques.

Are There Age-Related Differences in Effects of Positive and Negative Emotions in Arithmetic?

We investigated effects of emotions on arithmetic problem-solving and age-related differences in these effects. Young and older adults verified addition problems displayed superimposed on emotionally negative, positive, or neutral pictures. Participants obtained poorer performance in emotion than in neutral conditions, with stronger interference by negative than positive emotions. Also, participants were more impaired by negative emotions while solving true problems than false problems, whereas they were influenced by positive emotions similarly on true and false problems. Interestingly, effects of both positive and negative emotions were comparable in young and older adults. These findings have important implications for further understanding how negative and positive emotions influence arithmetic problem-solving.

Cooperative Service Placement and Request Routing in Mobile Edge Networks for Latency-Sensitive Applications

The emergence of mobile applications like self-driving cars, networked gaming, virtual reality, and augmented reality has created a demand for computation-intensive and latency critical applications. The dense deployment of base stations (BSs) makes the overlapping coverage of BS that induces the placement of services and routing the requests to the appropriate node is a challenging issue. Further, the limited resources at the edge node invite additional problems of allocating the existing limited edge resources cooperatively to fulfil the user demands. To address the problems mentioned above, we formulate the cooperative service placement and routing problem by placing the diversified latency critical services to maximize the time utility with the deadline and resource constraints. The problem is formulated as an integer linear programming problem for cooperative service placement in mobile edge networks. A greedy and randomized rounding technique is presented to solve the service caching and request routing problems decomposed from the proposed problem. Further, a heuristic algorithm based on the circular convex set is presented to solve the proposed NP-hard problem. Extensive simulation results demonstrate that the proposed cooperative service placement schemes significantly improve the delay, cache hit ratio, load on cloud, and time utility performance compared with existing mechanisms.

Affordances of fractions and decimals for arithmetic.

Rational numbers are represented by multiple notations: fractions, decimals, and percentages. Whereas previous studies have investigated affordances of these notations for representing different types of information (DeWolf et al., 2015; Tian et al., 2020), the present study investigated their affordances for solving different types of arithmetic problems. We hypothesized that decimals afford addition better than fractions do and that fractions afford multiplication better than decimals do. This hypothesis was tested in two experiments with university students (Ns = 77 and 80). When solving fraction and decimal arithmetic problems, participants converted addition problems from fraction to decimal form more than vice versa, and converted multiplication problems from decimal to fraction form more than vice versa, thus revealing preferences favoring decimals for addition and fractions for multiplication. Accuracies paralleled these revealed preferences: Addition accuracy was higher with decimals than fractions, whereas multiplication accuracy was higher with fractions than decimals. Variations in notation preferences as a function of the types of operands involved (e.g., equal vs. unequal denominator fractions) were more consistent with an explanation based on adaptive strategy choice (Siegler, 1996) than with one based on semantic interpretations associated with each notation. (PsycInfo Database Record (c) 2022 APA, all rights reserved).