@inbook {1007, title = {{\textquoteleft}Practicing place value{\textquoteright}: How children interpret and use virtual representations and features}, booktitle = {Proceedings of the Eleventh Congress of the European Society for Research in Mathematics Education }, year = {2019}, pages = {2941-2948}, publisher = {Freudenthal Group \& Freudenthal Institute, Utrecht University and ERME}, organization = {Freudenthal Group \& Freudenthal Institute, Utrecht University and ERME}, address = {Utrecht, the Netherlands}, author = {Schulz, Axel and Walter, Daniel}, editor = {Jankvist, U. T. and van den Heuvel-Panhuizen, M. and Veldhuis, M.} } @article {1008, title = {Stellenwerte verstehen und {\"u}ben}, journal = {F{\"o}rdermagazin Grundschule}, volume = {Heft 4/2019}, year = {2019}, pages = {10-16}, author = {Schulz, Axel and Walter, Daniel} } @inbook {967, title = {Stellenwertverst{\"a}ndnis festigen {\textendash} Potentiale und Nutzungsweisen einer Software zum Darstellungswechsel}, booktitle = {Beitr{\"a}ge zum Mathematikunterricht 2018}, year = {2018}, pages = {1667-1670}, publisher = {WTM-Verlag}, organization = {WTM-Verlag}, address = {M{\"u}nster}, author = {Schulz, Axel and Walter, Daniel}, editor = {Fachgruppe Didaktik der Mathematik der Universit{\"a}t Paderborn} }