Multiplication and division of fractions: numerical cognition development and assessment procedures

The number and its basic operations can be conceptualised within a general system of relations. Children need to construct a system of numbers within which they can add, subtract, multiply and divide any rational number. Products and quotients can be defined in terms of general relational schemes. In this study, we examine whether elementary school children can construct a system of numbers such that fraction multiplication and division are based on the construction of general relational schemes. Groups of students are not homogeneous and children progress at different rates. For reliable assessment teachers need methods to examine developmental and individual differences in cognitive representations of mathematical concepts and operations. A logistic regression curve offers a visualisation of the learning process as a function of average marks. The analysis of fraction multiplication and division items shows an improvement on correct response probability, especially for students with a higher average mark