[{"quality_controlled":"1","citation":{"apa":"Hattermann, M., vom Hofe, R., &#38; Kullmann, H. (2013). <i>An innovative approach to negative numbers based on the data of the PALMA-Project</i>. 37th Conference of the International Group for the Psychology of Mathematics Edu-cation, Kiel.","ieee":"M. Hattermann, R. vom Hofe, and H. Kullmann, “An innovative approach to negative numbers based on the data of the PALMA-Project,” presented at the 37th Conference of the International Group for the Psychology of Mathematics Edu-cation, Kiel, 2013.","short":"M. Hattermann, R. vom Hofe, H. Kullmann, in: 2013.","chicago":"Hattermann, M, R vom Hofe, and Harry Kullmann. “An innovative approach to negative numbers based on the data of the PALMA-Project,” 2013.","mla":"Hattermann, M., et al. <i>An innovative approach to negative numbers based on the data of the PALMA-Project</i>. 2013.","ama":"Hattermann M, vom Hofe R, Kullmann H. An innovative approach to negative numbers based on the data of the PALMA-Project. In: ; 2013.","bibtex":"@inproceedings{Hattermann_vom Hofe_Kullmann_2013, title={An innovative approach to negative numbers based on the data of the PALMA-Project}, author={Hattermann, M and vom Hofe, R and Kullmann, Harry}, year={2013} }"},"type":"conference","date_created":"2026-09-09T10:36:01Z","date_updated":"2026-09-09T10:36:09Z","title":"An innovative approach to negative numbers based on the data of the PALMA-Project","status":"public","year":"2013","jel":["I24"],"author":[{"first_name":"M","last_name":"Hattermann","full_name":"Hattermann, M"},{"first_name":"R","last_name":"vom Hofe","full_name":"vom Hofe, R"},{"id":"77972","last_name":"Kullmann","first_name":"Harry","orcid":"0000-0001-5488-5105","full_name":"Kullmann, Harry"}],"conference":{"end_date":"2013-07-30","start_date":"2013-07-30","name":"37th Conference of the International Group for the Psychology of Mathematics Edu-cation","location":"Kiel"},"user_id":"105186","_id":"67074","language":[{"iso":"ger"}]}]