The aim of this graduate thesis is to investigate opportunities for developing the concepts of perimeter and area in primary mathematics education. The theoretical framework of the study is based on the components of mathematical proficiency, including conceptual knowledge, procedural knowledge, strategic competence, adaptive reasoning, and productive disposition. The literature review encompasses research on the role of textbooks in mathematics education, phases in the development of measurement competency and specifics of learning and teaching perimeter and area. The methodology is based on a qualitative analysis of textbooks for primary mathematics education. Tasks related to perimeter and area were analysed to determine the extent to which they support the development measurement competency and of mathematical proficiency. This analysis identified key aspects in textbooks that could contribute to the continuous and progressive development of the concepts of perimeter and area. The research results indicate that the concepts of perimeter and area do not develop according to the literature recommendation. Namely, components of mathematical proficiency, properties of perimeter and area, and phases in the development of measurement competency are not adequately integrated. The study also suggests significant differences in how different textbooks approach tasks related to these concepts. The thesis provides guidelines for improving teaching materials and textbooks to ensure more consistent and comprehensive support for the development of students' mathematical abilities. It is recommended to focus more on integrating different components of mathematical proficiency in tasks related to perimeter and area and to introduce these concepts in the early grades of primary education corresponding to lower phases in the development of measurement competency.