[en] Successful control of basic mathematical operations must be one of the aims in compulsory stages of education. To this respect, previous research has shown that a high percentage of Primary Education school children (6-12 years old) make errors when having to solve subtraction (Brown and Burton, 1978; S?nchez, 2005; L?pez and S?nchez, 2007; VanLehn, 1982; Young and O?Shea, 1981). But not much is known about subtraction error among adults. For this reason, this dissertation was centered on university students, in order to analyze the errors and types of errors university students make when solving subtraction. To achieve this aim, 535 university undergraduate students from the Preschool and Primary school Teacher, B.A. in Small and Medium Business Management and Statistics Degrees from the University of Salamanca completed the questionnaire VanLehn (1990), containing twenty different types of subtractions. Wrong answers were categorized following error categorization established by VanLehn (1990) taking as reference the adaptation thereof by S?nchez (2005), to which other types of errors that came up from the analysis were also added. Results have shown that only one in four among university students were able to complete the whole subtraction questionnaire correctly; and that, from a total of 10700 subtraction operations solved, 1.258 (11.76%) had been done wrong. Analyzing the type of error made, the most frequent ones were the same systematic errors made by the school children. This can indicate that the types of error made at early stages of education when learning this algorithm are kept in the time, which may mean that the teaching and learning process to master this algorithm might not have been the appropriate one. In another sense, this dissertation offers new perspectives for the future, as it could have educational implications in order to improve the teaching and learning process of subtraction in early stages of school education.

[es] El manejo adecuado de las operaciones elementales es uno de los objetivos de la ense?anza obligatoria. En este sentido, investigaciones previas muestran que un alto porcentaje de ni?os de Educaci?n Primaria (6-12 a?os) cometen errores cuando realizan sustracciones (Brown y Burton, 1978; S?nchez, 2005; L?pez y S?nchez, 2007; VanLehn, 1982; Young y O?Shea, 1981). Sin embargo apenas se sabe si las personas adultas cometen errores. Por ello este trabajo se centr? en estudiantes universitarios, para analizar los errores y tipos de errores que cometen al efectuar sustracciones. Con ese objetivo, 535 estudiantes universitarios de las Diplomaturas y Grados de Maestro, Ciencias Empresariales y Pymes, y Estad?stica de la Universidad de Salamanca completaron el cuestionario de VanLehn (1990), compuesto por 20 sustracciones de diferentes tipos. Las respuestas err?neas se categorizaron a partir de las categor?as de errores de VanLehn (1990) tomando como referente la adaptaci?n de las mismas realizada por S?nchez (2005), a las que se a?adieron otros tipos de errores que surgieron del an?lisis. Los resultados mostraron que solamente una cuarta parte de los estudiantes universitarios realiz? correctamente todas las sustracciones del cuestionario y que, del total de 10.700 sustracciones, 1.258 (11?76%) hab?an sido resueltas de manera err?nea. Analizando el tipo de errores producidos, se observ? que los m?s frecuentes se corresponden con los errores sistem?ticos cometidos por los estudiantes de Educaci?n Primaria. Ello puede indicar que los tipos de errores cometidos en las edades de aprendizaje del algoritmo se mantienen con el tiempo, lo que puede suponer que la ense?anza y el aprendizaje del algoritmo de la sustracci?n pudo no haber sido el adecuado. En otro sentido, este estudio abre perspectivas de futuro y podr?a tener implicaciones educativas para favorecer la ense?anza y aprendizaje de la sustracci?n en las edades escolares.