Achieving inclusive mathematics education remains a distinctive challenge due to the discipline’s hierarchical structure, high degree of abstraction, and dense symbolism. These disciplinary features create unique cognitive barriers for students with special educational needs, requiring a precise intersection of content expertise and pedagogical scaffolding. While collaboration between mathematics and special education (SPED) teachers is vital to dismantling these barriers, the success of such teams is mediated by the teachers’ mental models—the internal assumptions that dictate their collaborative engagement. Utilizing a multi-case study design, this study examined teacher mental models through cross-disciplinary Lesson Study (LS) focused specifically on making abstract mathematical concepts accessible. Based on data collected before, during, and after four LS cycles, findings reveal that participants’ initial mental models of collaboration were limited to rudimentary idea-sharing. However, the LS experience facilitated a shift toward reciprocal learning, where participating teachers engaged in a mutual exchange of disciplinary expertise to co-create lesson resources and strategies. This shift is framed as a theoretical insight into cognitive syncretism: the restructuring of compartmentalized professional identities into a shared, integrated schema. Specifically, SPED teachers acquired the technical mathematical depth necessary to navigate cumulative curriculum demands, while mathematics teachers adopted differentiated strategies to decode complex mathematical symbols for diverse learners. Ultimately, this research positions mental models as primary mediators of educational reform, suggesting that sustainable inclusion in mathematics requires a fundamental cognitive reorganization of how teachers perceive the intersection of mathematical rigor and instructional accessibility.

This study outline design principles for teacher collaboration that can drive educational innovations and inclusion. Employing abductive analysis anchored on constructivist grounded theory, the study examined how the cyclical nature of Lesson Study (LS) can enhance the quality of teachers’ collaboration. The findings illustrate how a student-centered, transdisciplinary, and iterative form of collaboration fostered educational innovations and inclusion. This study further identified that context awareness, integration of support services, and distributed leadership during collaboration facilitated educational innovation and inclusive practices. The cyclical LS process empowered teachers to develop student-centered pedagogies, integrated technology, and adapted physical learning environments to ensure the success of diverse learners. The identified design principles aim to provide more targeted guidance for teacher training and professional development programs by defining the components of teacher collaboration. The findings of this study also offer practical insights for policymakers seeking to develop and support meaningful collaborative practices among teachers that can foster both inclusion and educational innovations.

The key idea of dimensional analysis is to see units of measurement as a crucial source of information for solving mathematical problems. Yet, this powerful tool is hardly at all mentioned in mathematics education research within secondary schools. Hence, this study explores dimensional analysis in secondary school with respect to its occurrence in high-stakes tests and whether teaching it could make students use it as a tool in mathematical problem solving. A first result from inspecting released national tests is that knowledge of the idea behind dimensional analysis seems useful on a substantial proportion of the test items. A second result from inspecting students’ archived responses to test items is that a large proportion of the students do not make use of the information contained in units of measurement. A third result is that an intervention on teaching the elements of dimensional analysis made students significantly improved their results from pre-test to post-test. Accordingly, we recommend teaching the key idea in dimensional analysis from lower secondary school as a tool for mathematical problem solving.

The key idea of dimensional analysis is to see units of measurement as a crucial source of information for solving mathematical problems. Yet, this powerful tool is hardly at all mentioned in mathematics education research within secondary schools. Hence, this study explores dimensional analysis in secondary school with respect to its occurrence in high-stakes tests and whether teaching it could make students use it as a tool in mathematical problem solving. An initial result from investigating some released national tests is that knowledge of the idea behind dimensional analysis seems useful on a substantial proportion of the test items. A second result from inspecting students’ archived responses to test items is that a large proportion of the students do not make use of the information contained in units of measurement. A third result is that an intervention on teaching the elements of dimensional analysis made students significantly improve their results from pre-test to post-test. Accordingly, we recommend teaching the key ideas in dimensional analysis from lower secondary school as a tool for mathematical problem solving.

This presentation introduces a new – and easy to implement – proximity coefficient 𝑃3for quantifying the degree of interleaving. Firth et al. (2021) contrasted interleaving andblock study to each other where the latter is to focus only one learning goal during asequence of exercises while interleaving means to intertwine different learning goals.Organising the order of exercises for students according to interleaving or block studyhas different consequences for students’ learning. In a post-test, Noh et al. (2016) foundthat when students had practiced according to interleaving, they achieved better on tasksthat required the students to integrate information. On the other hand, they also foundthat when students had practiced according to block-study, they achieved better on tasksthat required rule-based skills. Interleaving is relevant not only for the mathematicalcontent, but also for how the content is represented, namely, Rau et al. (2013) found thatstudents achieved better when the lesson design was to present learning goals asinterleaving and representations as block-study when compared to the opposite designof their classroom experiment.

Att ämnesintegrera matematik och ett annat ämne gör lektionerna intressantare genom att matematiken blir mer levande när den används för att modellera ett fenomen i ett annat ämne. Denna presentation ger några exempel på detta genom att använda databaser och enkla matematiska modeller för att undersöka aktuella frågor om samhälle och miljö, t ex livsstil och resvanor. Detta blir till miniprojekt på en lektion eller mer där matematik och ett naturvetenskapligt ämne knyts samman.

Boken presenterar forskningsgrundad didaktik om att formulera statistiska frågor, samla in och representera data grafiskt och numerisk samt dra slutsatser. Detta varvas med inslag av statistikens historia och undervisningsexempel som stöd för att med didaktisk design planera, genomföra och utvärdera undervisning i årskurs F–6.

Att observera insekter kan vara grund för ett samarbete mellan skolämnena biologi, naturkunskap och matematik och att ämnesinnehållet går att variera från tidiga skolår till gymnasiet. Värt att notera är att de framstående statistikerna Adolphe Quetelet, Karl Pearson och Ronald Fischer arbetade mycket med biologiska data. Men har du funderat på vilken matematik som ligger bakom att räkna insekter? Denna artikel visar att det inte på långt när räcker med att kunna räkneramsan. Det behövs även statistik, teoretisk och praktisk geometrisk problemlösning och en förmåga att formulera och lösa öppna problem av typen ”hur ska vi redovisa resultatet?”. Exempelvis ett stolpdiagram redan i lågstadiet, lägesmått och trianglars area från och med mellanstadiet, spridningsmått i högstadiet och hypotesprövning i gymnasiet.

Lesson Study (LS) is one of the collaborative practices that fosters deep interdependence among teachers. This deeper level of collaboration is vital in producing educational innovations that can lead to a more inclusive learning environment. Thus, this paper describes specific educational innovations that could promote inclusive learning environments developed and implemented by teachers during LS implementations. Using phenomenography, this study found various educational innovations emphasizing student-centered pedagogies, technology integration, and learning space modifications designed to address students' diverse needs during the teaching and learning process. Further data analyses also showed that the collaborations through LS fostered teachers' awareness of diverse learner needs, promoted student-centered planning, and encouraged input from veteran, novice, and special education teachers. These features of LS collaborations are crucial in developing inclusive and innovative practices. The findings from this study can help decision-makers optimize interventions, allocate resources strategically, and gain timely feedback on the impact of educational initiatives, such as LS, on the teaching and learning processes.

One of the institutionalized collaborative practices among teachers and other educators is the conduct of lesson study (LS). Considering the growing interest in the potential of LS to improve the quality of education through collaboration, it is worth exploring its potential contribution to enhancing the teaching competencies of teachers. This study determined the effects of LS on the teaching competencies as perceived by preservice and in-service teachers in mathematics and special education. A quasi-experimental study was undertaken in two selected middle schools (years 7–10). The participants’ perceived teaching competencies before and after the four LS cycles were determined using a survey questionnaire with indicators grouped into four dimensions: concept of diversity, teaching methodology, support services, and community participation. The Wilcoxon Signed-Rank test demonstrated a statistically significant large difference ( r  = .85, Z  = 3.29, p  < .001) between the pre-survey ( Mdn  = 4.08) and post-survey ( Mdn  = 4.34) ranks of the experimental groups. In contrast, the teaching competency gains of participants in the control group were statistically small and insignificant ( r  = .05, Z  = 0.14, p  = .889). Qualitative data obtained through observations, document analyses, and interviews further demonstrated that LS provided opportunities for enhancing the experimental groups’ understanding of classroom diversity, inclusive pedagogical content knowledge, and teaching math skills. Moreover, this study revealed that LS participation fostered increased self-esteem, confidence, and a sense of ownership and accountability among the LS participants.