Resumen de The use of ratio and rate concepts by students in primary and secondary school
Salvador Castillo Bresó, Ceneida Fernández Verdú 
, Ana Paula Canavarro
This paper aims to analyse how primary and secondary school students use the concepts of ratio and rate when solving a ratio comparison problem. 954 primary and secondary school students (11-16 years old) solved a ratio comparison problem that involves four questions designed following the Reflection on the Activity-Effect Relationship mechanism. Students’ answers were inductively analysed generating categories in relation to students’ use of these concepts and the difficulties they revealed. Results have shown that a large number of students seems not to have the concept of ratio available during and at the end of secondary education, presenting difficulties not only with the identification of the multiplicative relationship between the extensive quantities but also with the norming techniques and with the referent.
