Effect of number structure and nature of quantities on secondary school students proportional reasoning

This study investigates the effect of the number structure (integer vs. non-integer ratios) and the nature of the quantities (discrete vs. continuous) on the performance of secondary school students and on the strategies they use when solving proportional and non-proportional word problems. 551 secondary school students from 1st to 4th grade solved a test with proportional and non-proportional problems in which the task variables mentioned before were manipulated. Results showed that number structure affected students performance and the strategies used differently for proportional and non-proportional problems along the grades. However, the nature of the quantities had no influence.