AU - شحاتة، محمد عبد المنعم AU - مصيلحي، نبيل صلاح AU - حسن، حسام ربيع الدسوقي AB - This research aimed to measure the effectiveness of using roundhouse strategy in developing the mathematical concepts for the preparatory stage pupils. The research sample consisted of (32) students for the experimental group and (30) students for the control group. The research was applied to a sample of middle school students in Salem-Ashtewi Preparatory Common School, Bir Al-Abed Educational Administration in the academic year 2018-2019. The research included five chapters. The first chapter tackled the general framework of the research. Then the second chapter tackled the theoretical framework and the research literature, its importance, foundations, characteristics and the difference between it and traditional learning, After that it tackled the strategy of roundhouse (its definition - its principles - how to apply it - its importance - its advantages - its feed backs) and also discussed the mathematical concepts and how to develop it And how to measure it, In the third chapter explained the preparation of experimental treatment tools including the student book in the unit (Similarities - Reverse Pythagoras) and the teacher guide to teach this unit using the strategy of roundhouse and the mathematical concepts. Finally the research of experimental procedures, and the fourth chapter tackled the results of the research, which showed the effectiveness of using the strategy of roundhouse in the development of mathematical concepts in the preparatory school students, and the presentation of recommendations and proposals for the research, and the fifth chapter presented a summary of the research. (Published abstract) http://search.shamaa.org/abstract_en.gif OP - ص ص. 146-172 T1 - فاعلية استراتيجية البيت الدائري في تنمية المفاهيم الرياضية لدى تلاميذ المرحلة الإعدادية [مقال] UL - https://foej.journals.ekb.eg/article_239818_981ec94611b5f9c5ddd2e4a4d3b37a80.pdf النص الكامل (PDF) 1 http://search.shamaa.org/fulltext.gif