J. Ainley, D. Pratt, and A. Hansen, Connecting engagement and focus in pedagogic task design, British Educational Research Journal, vol.77, issue.3, pp.23-38, 2006.
DOI : 10.1080/01411920500401971

M. Behr, S. Erlwanger, and E. Nichols, How children view equality sentences No. PMDC- TR-3), 1976.

T. Carpenter and L. Levi, Developing conceptions of algebraic reasoning in the primary grades. (Res. Rep. 00-2), National Center for Improving Student Learning and Achievement in Mathematics and Science, 2000.

A. Disessa and B. Sherin, What changes in conceptual change?, International Journal of Science Education, vol.2, issue.10, pp.1155-1191, 1998.
DOI : 10.1119/1.12525

W. Dörfler, Inscriptions as objects of mathematical activities, 2006.

. Schloeglmann, New mathematics education research and practice, pp.97-111

E. M. Gray and D. O. Tall, Duality, Ambiguity, and Flexibility: A "Proceptual" View of Simple Arithmetic, Journal for Research in Mathematics Education, vol.25, issue.2, pp.116-140, 1994.
DOI : 10.2307/749505

D. Hewitt, Approaching arithmetic algebraically, Mathematics Teaching, vol.163, pp.19-29, 1998.

I. Jones, Meaningful engagement with the structure of equality statements. Working Papers of the Warwick Suminer Group

I. Jones, The design of equality statements, Working Papers of the Warwick Suminer Group, pp.63-82, 2006.

C. Kieran, Concepts associated with the equality symbol, Educational Studies in Mathematics, vol.73, issue.3, pp.317-326, 1981.
DOI : 10.1007/BF00311062

E. Knuth, A. Stephens, N. Mcneil, and M. Alibali, Does understanding the equals sign matter? evidence from solving equations, Journal for Research in Mathematics Education, vol.37, issue.4, pp.297-312, 2006.

N. Mcneil and M. W. Alibali, Why Won't You Change Your Mind? Knowledge of Operational Patterns Hinders Learning and Performance on Equations, Child Development, vol.26, issue.4, pp.883-899, 2005.
DOI : 10.1006/jmla.2001.2834

R. Noss and C. Hoyles, Windows on Mathematical Meanings: Learning Cultures and Computers, 1996.
DOI : 10.1007/978-94-009-1696-8

S. Papert, An exploration in the space of mathematics educations, International Journal of Computers for Mathematical Learning, vol.1, issue.1, pp.95-123, 1996.
DOI : 10.1007/BF00191473