@conference {428001,
	title = {Negative numbers as an epistemic difficult concept. Some lessons from history.},
	booktitle = {History and Pedagogy of Mathematics. Satellite Meeting of International Congress on Mathematical Education 11, 14 - 18 July 2008.},
	year = {2008},
	publisher = {Centro Cultural del M{\'e}xico Contemporan{\'e}o},
	organization = {Centro Cultural del M{\'e}xico Contemporan{\'e}o},
	abstract = {<p>Historical studies on the development of mathematical concepts will serve mathematics teachers to relate their students difficulties in understanding to conceptual problems in the history of mathematics. We argue that one popular tool for teaching about numbers, the number line, may not be fit for early teaching of operations involving negative numbers. Our arguments are drawn from the many discussions on negative numbers during the seventeenth and eighteenth centuries from philosophers and mathematicians as Arnauld, Leibniz, Wallis, Euler and dAlembert. Not only the division by negative numbers poses problems for the number line, but also the very idea of quantities smaller than nothing has been challenged. Drawing lessons from the history of mathematics we argue for the introduction of negative numbers in education within the context of symbolic operations.</p>},
	author = {Heeffer, Albrecht},
	editor = {Tzanakis, C.}
}
