An examination of Japanese curriculum materials through quantitative and covariational reasoning: the treatment of linear functions

In this study, we investigated how Japanese curriculum materials represent functional relationships through the lenses of quantitative and covariational reasoning. Utilizing macro and micro analyses, we analyzed Japanese elementary and lower secondary-level curriculum materials, including course of study, teachers' guide, and Mathematics International textbook series. We analyzed a set of statements and explanations in the course of study and the teachers' guide. We examined tasks, questions, and representations in the textbooks. Findings showed that Japanese curriculum materials attentively focus on learners' quantitative and covariational reasoning starting from 4th grade by the end of 8th grade. Particularly, Japanese curriculum materials have a spiral nature that supports learners' covariational reasoning gradually building up to continuous covariation in learning functional relationships involved in proportional and linear situations. We discuss the possible implications of this study for teachers, teacher educators, curriculum developers, and textbook writers.