Estrategias de cálculo mental para sumas y restas desarrolladas por estudiantes de secundaria

Abstract

Mental calculation strategies play an important role in the development of students’ number sense. In this regard, we sought to determine how students of a public middle school (distance education program), located in a rural community in the state of Hidalgo, Mexico, can develop mental calculation strategies when performing tasks involving addition and subtraction, in a shopping context. Eight different strategies were identified, some of which used fantasy money as a representation system that helped students to decompose quantities. They referred to strategies used by people, without schooling, when they receiving money back after paying for a purchase in the market. Strategies such as removing one to the minuend in a subtraction with regrouping also appeared, to obtain one addition without regrouping. That is, we identified a transfer of mental calculation strategies to paper and pencil scenarios, which facilitate calculations to solve a problem. This is an indicator of creativity and understanding of numbers and operations.