Proportionalitet är ett centralt begrepp i skolmatematiken. Begreppet introduceras i de lägre stadierna och återkommer i så gott som samtliga kurser från årskurs 9 tillsista kursen på gymnasiet. Det övergripande syftet med denna studie är att undersöka hur det matematiska begreppet proportionalitet hanteras i den svenska gymnasieskolan. En generell problematik kopplad till detta syfte är hur skolans styrdokument realiseras i läromedel och nationella prov. Fokus för denna avhandling har varit hur proportionalitet hanteras i det svenska gymnasiet i kursen Matematik A i några läromedel och nationella prov. För att undersöka detta utvecklades ett analysverktyg utifrån det teoretiska ramverket i ATD (Anthropological Theory of the Didactic). Av intresse är här relationer mellan de olika nivåerna i den didaktiska transpositionen, som berör just hur skolans styrdokument realiseras i läromedel och nationella prov. För det empiriska studiet av materialet användes från ATD begreppet matematisk organisation, genom att använda ett analysverktyg för att granska typer av uppgifter om proportionalitet, lösningstekniker och teoretiska modeller för proportionalitetsbegreppet.

De data som presenterats i denna studie ger en ganska ostrukturerad bild av de matematiska organisationer av begreppsområdet proportionalitet som presenteras i läromedel och i nationella prov och de ser även olika ut när det gäller hur proportionalitet hanteras i läromedlen respektive det nationella provet för Matematik A. Resultatet visar att ungefär var fjärde uppgift i de studerade kapitlen och de nationella proven berör proportionalitet men att begreppet hanteras ensidigt vad avser uppgiftstyp. Skillnader observerades mellan läromedel och nationella prov när det gäller hur lösningstekniker rekommenderas för olika typer av proportionalitetsuppgifter. De två teoretiska modeller för proportionalitet som har undersökts, dvs. statisk och dynamisk proportionalitet, finns representerade i ungefär lika omfattning i både läromedel och nationella prov. Vid uppgifter inom geometri handlar det dock ofta om statisk proportionalitet medan det inomområdet funktioner är vanligare att använda dynamisk proportionalitet.

Lärare bör få kunskap om skillnader mellan läromedel och läroplaner, och hur dessa tolkas i nationella prov, så att de i sin verksamhet kan välja det undervisningsinnehåll, inklusive övningsuppgifter, som ger en god variation för eleven kopplat till kursplanernas mål

Proportionality is a key concept in school mathematics. It is introduced in the primary grades, and reappears in almost all mathematics courses from Grade 9 to the last course in upper secondary school. The overall aim of this study is to investigate how the mathematical concept of proportionality is handled in the Swedish upper secondary school. A general problem connected to this end is how the national curriculum is realised in textbooks and national examinations. The focus of this thesis is on how proportionality is handled in the first Swedish upper secondary course in mathematics in some textbooks and national examinations. To examine this an analysis tool based on the theoretical framework of the ATD (Anthropological Theory of the Didactic) was developed. Of interest here are relations between the different levels in the didactic transposition, concerned with exactly how the national curriculum is realised in textbooks and national examinations. For the empirical study of the material the ATD concept of mathematical organisation was used, employing an analytical tool to examine the types of tasks dealing with proportionality, techniques for solving these tasks, and theoretical models for the concept of proportionality.

The data presented in this study gives a fairly unstructured picture of the mathematical organisations of the conceptual field of proportionality, as presented in textbooks and in the national tests. They also look different when it comes to how proportionality is handled in the textbooks and the national test for "Matematik A". The result shows that about every fourth task of the chapters and the national tests studied involved proportionality, but that there was a low variation in terms of types of tasks. Differences were observed between textbooks and national tests in terms of how solution techniques are recommended for different types of proportionality tasks. The two theoretical models of proportionality that were studied, ie. static and dynamic proportionality, are represented to approximately the same extent in both textbooks and national examinations. In geometry, it is often static proportionality, while in the field of functions it is common to use dynamic proportionality.

Teachers should have access to knowledge of the differences between textbooks and curricula, and how they are interpreted in the national tests, so that they can make deliberate choices in their teaching activities, including exercises, to support a good variety for students linked to curriculum objectives.

This article reports on an analysis of the process in which knowledge to be taught was transposed into knowledge actually taught, concerning a task including proportional relationships in an algebra setting in a grade 6 classroom. We identified affordances and constraints of the task by describing the mathematical praxeology of the two different types of knowledge exposed, in the task as such and in the activity of the classroom. Through the teacher’s explicit process of reasoning, modeling, revising, solving, and repeatedly explaining the task, we found that the transposition of knowl- edge was seriously affected by the contextualization of the task. Modeling word problems about everyday situations has its limitations and can, as in this case, make the problem unsolvable unless it is accepted as a Btextbook task^ disguised as real but adjusted to the norms of school mathematics. Such constraints may obscure mathe- matical ideas afforded by the task. We conclude that learning opportunities embedded in a task do not necessarily surface when a task is treated in a classroom setting

This case study explores how 12-13-year-old students encounter proportional reasoning while working with geometric patterning tasks using concrete materials. The focus is on the students’ use of spontaneous concepts when first dealing with such patterns in the context of collaborative work. Based on video recordings of a single lesson, a microgenetic analysis was performed to identify students’ learning trajectories, starting with students familiarizing themselves with pattern structure, followed by engagement in proportional reasoning, and ending with students perceiving a new technique to handle a situation where proportional reasoning did not suffice. While some student groups were able to move along the whole trajectory, most groups, when facing challenges, regressed to simpler techniques. The results provide new insights into students’ learning trajectories, which can be used to support students’ progress in the context of student-teacher interaction.