Early adolescents' proportional reasoning on ?rate? problems

The study deals with qualitative features of proportional reasoning on dimensional intensive variables by eleven and thirteen year-old students. These features include types of comparison and types of strategies employed. Four proportional problems, varying in numerical and referential content were administered to 116 eleven year-olds and 137 thirteen year-olds. No significant age effect was found. The relative frequencies with which the type of...