The topic of this diploma thesis is Additional Mathematics Class in the 4th Grade of Primary School. The paper offers an overview of the teaching content that is adopted in the 4th grade of primary school in mathematics according to the Teaching Plan and Programme and the National Curriculum for Preschool, Primary and Secondary Education. The paper describes the role and organization of Additional Mathematics Class, which includes fun tasks, as well as tasks that are necessary to prepare students for mathematics competition. The paper offers a detailed overview of tasks that appear at county competitions for the 4th grade of primary school in the Republic of Croatia. The tasks are classified by adapting the existing model for the analysis of mathematical textbooks. The aim of the analysis was to examine the tasks that appear at county competitions in the Republic of Croatia to better prepare students for future competitions. The tasks were examined with respect to activity, domain, task presentation, and context. The results of the analysis showed that in the previous county competitions in mathematics, students were most expected to do activities related to calculations within the domain of numbers and equations. The presentation of tasks from county competitions is mostly textual, and considering the context, most of the tasks are without context or with intra-mathematical context.