Mixed numbers and fraction in general have been a problem for students not only in understanding the concept of itself, but also in understanding the operation of it, such as addition. Thus, supporting students in learning addition of mixed numbers is needed. The aim of this study is to develop a local instructional theory and materials related to…

This paper reports an exploration into Indonesian fourth graders' difficulties in fractions and their relation to the opportunity to learn fractions students got at schools. The concept of "opportunity to learn" is often considered as a framework to investigate possible reasons for students' difficulties. The data for this study was…