Αντωνόπουλος (Konstantinos Antonopoulos) Κωνσταντίνος, Τσιούνη (Paraskevι Tsiouni) Παρασκευή, and Ζαχάρος (Kostas Zacharos) Κώστας. 2008. “Solution Strategies on Addition Problems and Meanful Framework in Teaching”. Investigating the child’s World 8 (July):9-24. https://doi.org/10.12681/icw.18071.