This article deals with important aspects regarding the checking and assessment of the knowledge and skills of third-graders (more specifically pupils ending the third grade of primary school). The text makes use of the Omnibus research reports: M. Czajkowska, B. Szurowska (2016). It is worth noting that conducting tests in children of this age should be different than in adults (for example due to their emotional development, motivation, and self-esteem). The article is innovative in nature, because the authors pay attention to certain behaviors of the teachers and the children which have not been considered noteworthy before, such as: preparation of students, consisting not only of the key skills and knowledge determined by the requirements of the obligatory educational program but also providing emotional support, providing a pleasant atmosphere, indicating ways and methods of talking with children and parents about test results and supporting the children's development in the specific areas that need improvement. The behavior of the children during tests, e.g. the possibility of using the available tools (e.g. ruler, scissors, dictionary, etc.) and the ability to solve the problem and apply different strategies in an emotionally difficult situation. The data presented in the article allows to determine both the amount of skills and knowledge that third grade students have in the field of Polish and mathematics as well as to open a discussion about a new approach to conducting tests among young students (focused on the child, its needs and feelings, and understanding how important teacher-parent cooperation is for the development of children at this age).