Brocardo, JoanaSerrazina, LurdesRocha, Isabel2014-02-142014-02-142007-02978-9963-671-25-0http://hdl.handle.net/10400.26/5685The Project “Number sense development: curricular demands and perspectives” aims to study the development of number sense in elementary school (5 to 12 years old). This paper presents a discussion based on one of the six case studies developed by the project. We will focuses on the strategies used by 7-years old pupils when solving multiplication problems, namely on the awareness of existence of different strategies and the inclination to utilize an efficient representation or method.engconference object