The aim of the dissertation is to contribute with knowledge about mathematizing in preschools\, by empirically and analytically exa mining mathematizing as accomplished in children&rsquo\;s multimodal int eractions with each other and their pedagogues in everyday activities. T heoretically and analytically the dissertation is based on an ethnometho dological and conversation analytic perspective (EM/CA) (e.g. Goodwin\, 2000\; Heritage\, 1984)\, which highlights multimodal interaction and co mmunication in social contexts. Mathematizing is defined as participatio n in mathematical discourse (Sfard\, 2008). A special interest is direct ed to how preschool children use talk\, embodied actions and other semio tic resources as they orient to mathematics in play and other activities . The dissertation is based on ethnographic fieldwork combined with vide o recordings of everyday mathematizing in two Swedish preschools with ch ildren 3&ndash\;5 years old.

\n\nThe findings are presented in thr
ee studies. \;*The first study* \;examines how mathematic
al activities emerge in children&rsquo\;s interactions with each other a
nd with their pedagogues. Whether it is the children or the pedagogues w
ho initiate the activity\, the children are shown to be actively involve
d in the construction of the emerging mathematical content. Geometric sh
apes as well as different aspects of number sense are a couple of the ma
thematical topics covered in the study. \;*The second study*&
nbsp\;explores children&rsquo\;s mathematizing in the block play area\,
with an interest in preschoolers&rsquo\; displayed understandings of geo
metry (spatiality\, shape\, symmetry) (Seo\, 2003). The study demonstrat
es how the participants orient to different spatial phenomena as they wo
rk with a construction toy. The children are shown to rely upon verbal a
nd embodied resources such as deictics and pointing gestures as geometri
cal aspects are actualized in their interaction. \;*The third stu
dy* \;investigates mathematizing with an interest in how geometr
ical shapes are made relevant in interaction in two consecutive pedagogi
cal activities: reading and painting. The results of the study demonstra
te how naming (baptizing) (Sfard\, 2008) of geometrical shapes are centr
al in the two activities. In the painting activity an aesthetic dimensio
n was actualized in the children&rsquo\;s discourse\, that somewhat obsc
ured the mathematical content in the activity. The study thus shows the
complexity of the relations between the activities. Together the studies
contribute with knowledge on preschool children&rsquo\;s everyday mathe
matizing\, in particular children&rsquo\;s appropriation of a geometric
discourse as it emerges in the unfolding flow of multimodal interaction.
Through the use of an EM/CA perspective the dissertation contributes wi
th new theoretical and methodological approaches to research on mathemat
ics in preschools. \;