Bu araştırmanın amacı ortaokul beşinci sınıf öğrencilerinin toplama-çıkarma işlemi yaparken kullandıkları ve tercih ettikleri ideal zihinden hesaplama stratejilerini belirlemektir. Nitel araştırma modellerinden özel durum çalışmasına göre desenlenen bu araştırma, 2014-2015 güz döneminde gerçekleştirilmiştir. Araştırma, bir devlet ortaokulunda öğrenim gören 16’sı erkek 17’si kız olmak üzere toplam 33 beşinci sınıf öğrencisiyle gerçekleştirilmiştir. Araştırmanın verileri araştırmacılar tarafından geliştirilmiş etkinlik temelli yarı yapılandırılmış görüşme formu ile toplanmıştır. Görüşme formundan elde edilen veriler mevcut zihinden toplama ve çıkarma yapma stratejilerine göre betimsel olarak çözümlenmiştir. Araştırmadan elde edilen sonuçlara göre toplama işleminde öğrencilerin en fazla “onluklara ve birliklere ayırarak ekleme” stratejisini, en az ise “sayıları onu referans alarak parçalama” stratejisini kullandıkları belirlenmiştir. Çıkarma işleminde ise öğrencilerin en fazla “onar onar eksiltme” stratejisini, en az ise “onlukları ve birlikleri ayırarak çıkarma” stratejisini kullandıkları tespit edilmiştir. Buna rağmen çoğu öğrencinin zihinden toplama ve çıkarma işlemlerine yönelik herhangi bir stratejiyi doğru şekilde kullanmadığı ya da bu sorulara cevap vermediği belirlenmiştir. Öğrencilerin tercih edilen zihinden hesaplamaları değerlendirmeleri incelendiğinde, büyük oranda kullandıkları stratejiler yönünde tercihte bulundukları tespit edilmiştir.
References
Australian Education Council. (1991). A national statement on mathematics for Australian schools. Melbourne: Curriculum Corporation.
Baroody, A.J. (2006). Why children have difficulties mastering the basic number combinations and how to help them. Teaching Children Mathematics, 13(1), 22-31.
Beishuizen, M. (2001). Different approaches to mastering mental calculation strategies. In J. Anghileri (Ed.), Principles and Practices in Arithmetic Teaching-Innovative Approaches for the Primary Classroom (pp. 119-130). Buckingham: Open University Press.
Beishuizen, M. (1993). Mental strategies and materials or models for addition and subtraction up to 100 in Dutch second grades. Journal for Research in Mathematics Education, 24(4), 294-323.
Beishuizen, M., Wolters, G., & Broers, G. (1991). Research into mental computation procedures in the number domain 20-100 using response times and speed tests. Tijdschrift voor Onderwijsresearch, 16, 19-38.
Blote, A.W., Klein, A.S., & Beishuizen, M. (2000). Mental computation and conceptual understanding. Learning and Instruction, 10, 221-247.
Buys, K. (2008). Mental arithmetic. In M. van den Heuvel-Panhuizen (Ed.), Children learn mathematics: A learning-teaching trajectory with ıntermediate attainment targets for calculation with whole numbers in primary school (pp. 121-146) Netherlands: Sense Publishers.
Buys, N., Teunissen, F., & Van Bergen, T. (1981). Teachers’ manual “operatoir rekenen”: 2nd grade. Tilburg, The Netherlands: Zwijsen.
Carpenter, T.P., Franke, M.L., Jacobs, V.R., Fennema, E., & Empson, S.B. (1998). A longitudinal study of invention and understanding in children’s multidigit addition and subtraction. Journal of Research in Mathematics Education, 29(1), 3-20.
Carraher, T.N., Carraher, D.W., & Schliemann, A.D. (1987). Written and oral mathematics. Journal for Research in Mathematics Education, 18, 83-97.
Ceylan, S., & Özdemir, A.Ş. (2012). Nihayetul-elbab adlı eserde kullanılan zihinden hesap yöntemlerinin 6.sınıf öğrencilerinin zihinden hesap ve tahmin becerilerine etkisi. X. Ulusal Fen Bilimleri ve Matematik Eğitimi Kongresi, Niğde Üniversitesi, Niğde, Türkiye.
Cooper, T.J., Heirdsfield, A., & Irons, C. (1995). Year 2 and 3 children’s strategies for mental addition and subtraction. In B. Atweh & S. Flavel (Eds.), GALTHA (pp. 195-202). Darwin: MERGA Inc.
Creswell, J.W. (2013). Qualitative inquiry and research design: Choosing among five traditions (3rd Ed.). California: Sage Publication.
Çavuş Erdem, Z., & Duran, H. (2015). Yetişkinlerin zihinden hesaplama becerilerinin özellikleri üzerine karşılaştırmalı bir çalışma. Türk Bilgisayar ve Matematik Eğitimi Dergisi, 6(3), 463-482.
De Corte, E., & Verschaffel, L. (1987). The effect of semantic structure on first graders’ strategies for solving addition and subtraction word problems. Journal for Research in Mathematics Education, 18(5), 363-381.
Department of Education and Science. (1987). Mathematics from 5-16 (2nd Ed.). London: Curriculum Matters 3AN HMT Series.
Glesne, C. (2013). Nitel araştırmaya giriş (2.Basım) (Çev. A. Ersoy & P. Yalçınoğlu). Ankara: Anı Yayıncılık.
Heirdsfield, A. (2002). Inaccurate mental addition and subtraction: Causes and compensation. In B. Barton, K.C. Irwin, M. Pfannkuch & M.O.J. Thomas (Eds.), Mathematics education in the south pasific (pp. 334-341). Auckland: MERGA Inc.
Heirdsfield, A. (2001). Integration and compensation in accurate mental computation. In J. Bobis, B. Perry & M. Mitchelmore (Eds.), Numeracy and beyond (pp. 273-280). Sydney: MERGA Inc.
Heirsfield, A., & Cooper, T.J. (2004a). Factors affecting the process of proficient mental addition and subtraction: Case studies of flexible and inflexible computers. Journal of Mathematical Behavior, 23, 443-463.
Heirdsfield, A., & Cooper, T.J. (2004b). Inaccurate mental addition and subtraction: Causes and compensation. Focus on Learning Problems in Mathematics, 26(3), 43-66.
Heirdsfield, A., & Cooper, T.J. (1996). The “ups” and “downs” of substraction: Young children’s additive and subtractive mental strategies for solutions of subtraction word problems and algorithmic exercises. In P. Clarkson (Ed.), Technology in mathematics education (pp. 261-268). Melbourne: MERGA Inc.
Henry, V., & Brown, R. (2008). First-grade basic facts. Journal for Research in Mathematics Education, 39, 153-183.
Karasar, N. (2005). Bilimsel araştırma yöntemi. Ankara: Nobel Yayın Dağıtım.
Klein, T., & Beishuizen, M. (1994). Assessment of flexibility in mental arithmetic. In J.E.H. LuitVan (Ed.), Research on learning and instruction in kindergarten and primary school (pp. 125-152). Doetinchem, The Netherlands: Graviatt Publishing Company.
McIntosh, A., & Dole, S. (2000). Mental computation, number sense and general mathematics ability: Are they linked?. In J. Bana & A. Chapman (Eds.), Mathematics education beyond 2000 (pp. 401-408). Perth: MERGA Inc.
Merriam, S. (2013). Nitel araştırma-desen ve uygulama için bir rehber (Çev. S. Turan). Ankara: Nobel Yayınevi.
Miles, B.M., & Huberman, M.A. (1994). Qualitative data analysis. London: Sage Publication.
Morais, C., & Serrazina, L. (2013). Mental computation strategies in subtraction problem solving. In B. Ubuz (Ed.), CERME 8 (pp. 333-342), Ankara: Middle East of Technical University.
MEB (Milli Eğitim Bakanlığı). (2015). Ortaokul matematik 5.sınıf ders kitabı. Ankara: Özgün Matbaacılık.
MEB (Milli Eğitim Bakanlığı). (2014). Ortaokul matematik 5.sınıf ders kitabı. Ankara: Pasifik Yayınları.
MEB (Milli Eğitim Bakanlığı). (2009). İlköğretim matematik dersi 6-8.sınıflar öğretim programı. Ankara: Milli Eğitim Basımevi.
National Curriculum for England. (1999). Mathematics. Department of Education and Employment, London: Qualifications and Curriculum Authority.
Nelissen, J. (1980). The theory of gal’perin in discussion. Pedagogische Studien, 57, 305-321.
NCTM (National Council of Teachers of Mathematics). (2000). Principles and standards for school mathematics. Reston: NCTM Publishing.
Pesen, C. (2004). Zihinden toplama ve çıkarma işlemlerinde kullanılan yöntemlerin ilköğretim 1.sınıf öğrencilerinin başarı düzeyine etkisi. Ege Eğitim Dergisi, 5, 17-23.
Piaget, J. (1976). The psychology and intelligence in children. New York: International Universities Press.
Resnick, L.B. (1986). The development of mathematical intuition. In M. Parlmutter (Ed.), Perspectives on intellectual development: The minnesota symposium on child development (pp. 159-194). Hillsdale, NJ: Erlbaum.
Reys, R.E. (1984). Mental computation and estimation: Past, present and future. Elementary School Journal, 84(5), 546-557.
Reys, B.J., & Barger, R.H. (1994). Mental computation: Issues from united states perspectives. In R.E. Reys & N. Nohda (Eds.), Computational alternatives for the twenty-first century (pp. 31-47). Reston: NTCM Publishing.
Reys, R.E., Reys, B.J., Nohda, N., & Emori, H. (1995). Mental computation performance and strategy use of japanese students in grades 2, 4, 6 and 8. Journal for Research in Mathematics Education, 26(4), 304-326.
Rubenstein, N. (2001). Mental mathematics beyond the middle school. Mathematics Teacher, 94(6), 442-447.
Ruesink, N., & Heuvel-Panhuizen, M.V.D. (1991). Use of strategies with a number problem end of third grade. Panamapost, 9, 15-25.
Saxe, G.B. (1988). The mathematics of child street vendors. Child Development, 1415-1425.
Sowder, J.T. (1990). Mental computation and number sense. The Arithmetic Teacher, 37(7), 18-20.
Sowder, J.T. (1988). Making sense of numbers in school mathematics. In G. Leinhardt, R. Putman & R. Hattrup (Eds.), Analysis of arithmetic for mathematics, Hillsdale, NJ: Erlbaum.
Trafton, P.R. (1978). Estimation and mental arithmetic: Important components of computation. In M. Suydam & R.E. Reys (Eds.), Developing computational skills (pp. 196-213). Reston: NCTM Publishing.
Treffers, A., & De Moor, E. (1990). Towards a national mathematics curriculum for the elementary school. Part 2: Basic skills and written computation. Zwijssen, Tilburg, The Netherlands.
Van de Walle, J.A. (1994). Elementary school mathematics: Teaching developmentally. New York: Longman.
Van de Walle, J.A., Karp, K., & Bay-Williams, J. (2014). Elementary and middle school mathematics teaching developmentally (8th Ed.). Essex, England: Pearson.
Van Mulken, F. (1992). Mental arithmetic and strategic action-two basic forms of addition and subtraction up to hundred. Unpublished doctoral dissertation, Leiden University, Leiden, The Netherlands.
Wyatt, J.W. (1985). A case-study survey of computational estimation processes and notions of reasonableness among ninth grade students. Unpublished Doctoral Dissertation, University of Missouri, Columbia, USA.
Willis, S. (1990). Numeracy and society: The shifting ground. In S. Willis (Ed.), Being numerate: What counts? (pp. 1-23). Melbourne: ACER.
Yazgan, Y., & Bintaş, J. (2005). İlköğretim dördüncü ve beşinci sınıf öğrencilerinin problem çözme stratejilerini kullanabilme düzeyleri: Bir öğretim deneyi. Hacettepe Üniversitesi Eğitim Fakültesi Dergisi, 28, 210-218.
Yazgan, Y., Bintaş, J., & Altun, M. (2002). İlköğretim beşinci sınıf öğrencilerinin zihinden hesap ve tahmin becerilerinin geliştirilmesi. V. Ulusal Fen Bilimleri ve Matematik Eğitimi Kongresi, Orta Doğu Teknik Üniversitesi, Ankara, Türkiye.
Yıldırım, A., & Şimşek, H. (2008). Sosyal bilimlerde nitel araştırma yöntemleri (6.Basım). Ankara: Seçkin Yayıncılık.
Australian Education Council. (1991). A national statement on mathematics for Australian schools. Melbourne: Curriculum Corporation.
Baroody, A.J. (2006). Why children have difficulties mastering the basic number combinations and how to help them. Teaching Children Mathematics, 13(1), 22-31.
Beishuizen, M. (2001). Different approaches to mastering mental calculation strategies. In J. Anghileri (Ed.), Principles and Practices in Arithmetic Teaching-Innovative Approaches for the Primary Classroom (pp. 119-130). Buckingham: Open University Press.
Beishuizen, M. (1993). Mental strategies and materials or models for addition and subtraction up to 100 in Dutch second grades. Journal for Research in Mathematics Education, 24(4), 294-323.
Beishuizen, M., Wolters, G., & Broers, G. (1991). Research into mental computation procedures in the number domain 20-100 using response times and speed tests. Tijdschrift voor Onderwijsresearch, 16, 19-38.
Blote, A.W., Klein, A.S., & Beishuizen, M. (2000). Mental computation and conceptual understanding. Learning and Instruction, 10, 221-247.
Buys, K. (2008). Mental arithmetic. In M. van den Heuvel-Panhuizen (Ed.), Children learn mathematics: A learning-teaching trajectory with ıntermediate attainment targets for calculation with whole numbers in primary school (pp. 121-146) Netherlands: Sense Publishers.
Buys, N., Teunissen, F., & Van Bergen, T. (1981). Teachers’ manual “operatoir rekenen”: 2nd grade. Tilburg, The Netherlands: Zwijsen.
Carpenter, T.P., Franke, M.L., Jacobs, V.R., Fennema, E., & Empson, S.B. (1998). A longitudinal study of invention and understanding in children’s multidigit addition and subtraction. Journal of Research in Mathematics Education, 29(1), 3-20.
Carraher, T.N., Carraher, D.W., & Schliemann, A.D. (1987). Written and oral mathematics. Journal for Research in Mathematics Education, 18, 83-97.
Ceylan, S., & Özdemir, A.Ş. (2012). Nihayetul-elbab adlı eserde kullanılan zihinden hesap yöntemlerinin 6.sınıf öğrencilerinin zihinden hesap ve tahmin becerilerine etkisi. X. Ulusal Fen Bilimleri ve Matematik Eğitimi Kongresi, Niğde Üniversitesi, Niğde, Türkiye.
Cooper, T.J., Heirdsfield, A., & Irons, C. (1995). Year 2 and 3 children’s strategies for mental addition and subtraction. In B. Atweh & S. Flavel (Eds.), GALTHA (pp. 195-202). Darwin: MERGA Inc.
Creswell, J.W. (2013). Qualitative inquiry and research design: Choosing among five traditions (3rd Ed.). California: Sage Publication.
Çavuş Erdem, Z., & Duran, H. (2015). Yetişkinlerin zihinden hesaplama becerilerinin özellikleri üzerine karşılaştırmalı bir çalışma. Türk Bilgisayar ve Matematik Eğitimi Dergisi, 6(3), 463-482.
De Corte, E., & Verschaffel, L. (1987). The effect of semantic structure on first graders’ strategies for solving addition and subtraction word problems. Journal for Research in Mathematics Education, 18(5), 363-381.
Department of Education and Science. (1987). Mathematics from 5-16 (2nd Ed.). London: Curriculum Matters 3AN HMT Series.
Glesne, C. (2013). Nitel araştırmaya giriş (2.Basım) (Çev. A. Ersoy & P. Yalçınoğlu). Ankara: Anı Yayıncılık.
Heirdsfield, A. (2002). Inaccurate mental addition and subtraction: Causes and compensation. In B. Barton, K.C. Irwin, M. Pfannkuch & M.O.J. Thomas (Eds.), Mathematics education in the south pasific (pp. 334-341). Auckland: MERGA Inc.
Heirdsfield, A. (2001). Integration and compensation in accurate mental computation. In J. Bobis, B. Perry & M. Mitchelmore (Eds.), Numeracy and beyond (pp. 273-280). Sydney: MERGA Inc.
Heirsfield, A., & Cooper, T.J. (2004a). Factors affecting the process of proficient mental addition and subtraction: Case studies of flexible and inflexible computers. Journal of Mathematical Behavior, 23, 443-463.
Heirdsfield, A., & Cooper, T.J. (2004b). Inaccurate mental addition and subtraction: Causes and compensation. Focus on Learning Problems in Mathematics, 26(3), 43-66.
Heirdsfield, A., & Cooper, T.J. (1996). The “ups” and “downs” of substraction: Young children’s additive and subtractive mental strategies for solutions of subtraction word problems and algorithmic exercises. In P. Clarkson (Ed.), Technology in mathematics education (pp. 261-268). Melbourne: MERGA Inc.
Henry, V., & Brown, R. (2008). First-grade basic facts. Journal for Research in Mathematics Education, 39, 153-183.
Karasar, N. (2005). Bilimsel araştırma yöntemi. Ankara: Nobel Yayın Dağıtım.
Klein, T., & Beishuizen, M. (1994). Assessment of flexibility in mental arithmetic. In J.E.H. LuitVan (Ed.), Research on learning and instruction in kindergarten and primary school (pp. 125-152). Doetinchem, The Netherlands: Graviatt Publishing Company.
McIntosh, A., & Dole, S. (2000). Mental computation, number sense and general mathematics ability: Are they linked?. In J. Bana & A. Chapman (Eds.), Mathematics education beyond 2000 (pp. 401-408). Perth: MERGA Inc.
Merriam, S. (2013). Nitel araştırma-desen ve uygulama için bir rehber (Çev. S. Turan). Ankara: Nobel Yayınevi.
Miles, B.M., & Huberman, M.A. (1994). Qualitative data analysis. London: Sage Publication.
Morais, C., & Serrazina, L. (2013). Mental computation strategies in subtraction problem solving. In B. Ubuz (Ed.), CERME 8 (pp. 333-342), Ankara: Middle East of Technical University.
MEB (Milli Eğitim Bakanlığı). (2015). Ortaokul matematik 5.sınıf ders kitabı. Ankara: Özgün Matbaacılık.
MEB (Milli Eğitim Bakanlığı). (2014). Ortaokul matematik 5.sınıf ders kitabı. Ankara: Pasifik Yayınları.
MEB (Milli Eğitim Bakanlığı). (2009). İlköğretim matematik dersi 6-8.sınıflar öğretim programı. Ankara: Milli Eğitim Basımevi.
National Curriculum for England. (1999). Mathematics. Department of Education and Employment, London: Qualifications and Curriculum Authority.
Nelissen, J. (1980). The theory of gal’perin in discussion. Pedagogische Studien, 57, 305-321.
NCTM (National Council of Teachers of Mathematics). (2000). Principles and standards for school mathematics. Reston: NCTM Publishing.
Pesen, C. (2004). Zihinden toplama ve çıkarma işlemlerinde kullanılan yöntemlerin ilköğretim 1.sınıf öğrencilerinin başarı düzeyine etkisi. Ege Eğitim Dergisi, 5, 17-23.
Piaget, J. (1976). The psychology and intelligence in children. New York: International Universities Press.
Resnick, L.B. (1986). The development of mathematical intuition. In M. Parlmutter (Ed.), Perspectives on intellectual development: The minnesota symposium on child development (pp. 159-194). Hillsdale, NJ: Erlbaum.
Reys, R.E. (1984). Mental computation and estimation: Past, present and future. Elementary School Journal, 84(5), 546-557.
Reys, B.J., & Barger, R.H. (1994). Mental computation: Issues from united states perspectives. In R.E. Reys & N. Nohda (Eds.), Computational alternatives for the twenty-first century (pp. 31-47). Reston: NTCM Publishing.
Reys, R.E., Reys, B.J., Nohda, N., & Emori, H. (1995). Mental computation performance and strategy use of japanese students in grades 2, 4, 6 and 8. Journal for Research in Mathematics Education, 26(4), 304-326.
Rubenstein, N. (2001). Mental mathematics beyond the middle school. Mathematics Teacher, 94(6), 442-447.
Ruesink, N., & Heuvel-Panhuizen, M.V.D. (1991). Use of strategies with a number problem end of third grade. Panamapost, 9, 15-25.
Saxe, G.B. (1988). The mathematics of child street vendors. Child Development, 1415-1425.
Sowder, J.T. (1990). Mental computation and number sense. The Arithmetic Teacher, 37(7), 18-20.
Sowder, J.T. (1988). Making sense of numbers in school mathematics. In G. Leinhardt, R. Putman & R. Hattrup (Eds.), Analysis of arithmetic for mathematics, Hillsdale, NJ: Erlbaum.
Trafton, P.R. (1978). Estimation and mental arithmetic: Important components of computation. In M. Suydam & R.E. Reys (Eds.), Developing computational skills (pp. 196-213). Reston: NCTM Publishing.
Treffers, A., & De Moor, E. (1990). Towards a national mathematics curriculum for the elementary school. Part 2: Basic skills and written computation. Zwijssen, Tilburg, The Netherlands.
Van de Walle, J.A. (1994). Elementary school mathematics: Teaching developmentally. New York: Longman.
Van de Walle, J.A., Karp, K., & Bay-Williams, J. (2014). Elementary and middle school mathematics teaching developmentally (8th Ed.). Essex, England: Pearson.
Van Mulken, F. (1992). Mental arithmetic and strategic action-two basic forms of addition and subtraction up to hundred. Unpublished doctoral dissertation, Leiden University, Leiden, The Netherlands.
Wyatt, J.W. (1985). A case-study survey of computational estimation processes and notions of reasonableness among ninth grade students. Unpublished Doctoral Dissertation, University of Missouri, Columbia, USA.
Willis, S. (1990). Numeracy and society: The shifting ground. In S. Willis (Ed.), Being numerate: What counts? (pp. 1-23). Melbourne: ACER.
Yazgan, Y., & Bintaş, J. (2005). İlköğretim dördüncü ve beşinci sınıf öğrencilerinin problem çözme stratejilerini kullanabilme düzeyleri: Bir öğretim deneyi. Hacettepe Üniversitesi Eğitim Fakültesi Dergisi, 28, 210-218.
Yazgan, Y., Bintaş, J., & Altun, M. (2002). İlköğretim beşinci sınıf öğrencilerinin zihinden hesap ve tahmin becerilerinin geliştirilmesi. V. Ulusal Fen Bilimleri ve Matematik Eğitimi Kongresi, Orta Doğu Teknik Üniversitesi, Ankara, Türkiye.
Yıldırım, A., & Şimşek, H. (2008). Sosyal bilimlerde nitel araştırma yöntemleri (6.Basım). Ankara: Seçkin Yayıncılık.
Duran, M., Doruk, M., & Kaplan, A. (2016). Ortaokul Öğrencilerinin Zihinden Hesaplama Yaparken Kullandıkları Stratejiler. İlköğretim Online, 15(3). https://doi.org/10.17051/io.2016.00048
AMA
Duran M, Doruk M, Kaplan A. Ortaokul Öğrencilerinin Zihinden Hesaplama Yaparken Kullandıkları Stratejiler. İOO. July 2016;15(3). doi:10.17051/io.2016.00048
Chicago
Duran, Murat, Muhammet Doruk, and Abdullah Kaplan. “Ortaokul Öğrencilerinin Zihinden Hesaplama Yaparken Kullandıkları Stratejiler”. İlköğretim Online 15, no. 3 (July 2016). https://doi.org/10.17051/io.2016.00048.
EndNote
Duran M, Doruk M, Kaplan A (July 1, 2016) Ortaokul Öğrencilerinin Zihinden Hesaplama Yaparken Kullandıkları Stratejiler. İlköğretim Online 15 3
IEEE
M. Duran, M. Doruk, and A. Kaplan, “Ortaokul Öğrencilerinin Zihinden Hesaplama Yaparken Kullandıkları Stratejiler”, İOO, vol. 15, no. 3, 2016, doi: 10.17051/io.2016.00048.
ISNAD
Duran, Murat et al. “Ortaokul Öğrencilerinin Zihinden Hesaplama Yaparken Kullandıkları Stratejiler”. İlköğretim Online 15/3 (July 2016). https://doi.org/10.17051/io.2016.00048.
JAMA
Duran M, Doruk M, Kaplan A. Ortaokul Öğrencilerinin Zihinden Hesaplama Yaparken Kullandıkları Stratejiler. İOO. 2016;15. doi:10.17051/io.2016.00048.
MLA
Duran, Murat et al. “Ortaokul Öğrencilerinin Zihinden Hesaplama Yaparken Kullandıkları Stratejiler”. İlköğretim Online, vol. 15, no. 3, 2016, doi:10.17051/io.2016.00048.
Vancouver
Duran M, Doruk M, Kaplan A. Ortaokul Öğrencilerinin Zihinden Hesaplama Yaparken Kullandıkları Stratejiler. İOO. 2016;15(3).