Argumentation is a vital component of teaching, fostering critical thinking, reasoning, and the justification of ideas among pupils. It involves constructing, presenting, and defending claims, as well as evaluating opposing viewpoints. Effective argumentation enhances students' problem-solving abilities and deepens their conceptual understanding.

This research explores the perspectives of pre-service mathematics and informatics teachers from Comenius University in Bratislava, Slovakia, regarding the integration of argumentation into their teaching practices. The study focuses on how they incorporate argumentation strategies into their lesson plans during their first year of masters studies. The analysis is grounded in the framework developed by AnnaMarie Conner and collective which examines the cognitive complexity and structure of argumentative practices.

The study reveals that while pre-service teachers can incorporate questions that prompt argumentation within their lesson plans, these questions can lack high cognitive demand. Many focus on basic comprehension rather than fostering deeper argumentative engagement. Informatics pre-service teachers primarily emphasize demonstrating methods and procedures, mathematics pre-service teachers tend to request ideas from pupils but often without follow-up prompts to further their reasoning.

The study highlights the need for training in high-level argumentation skills. With Slovakia's new curriculum set to emphasize argumentation in mathematics and informatics starting in 2026, it is essential to better prepare future teachers. Enhancing their ability to craft thought-provoking questions and facilitate discussions will better equip students for complex problem-solving in both academic and professional contexts.

Keywords: Pre-service teachers, Argumentation, Lesson plans, Mathematics education, Informatics education.