STEM education promotes the integration of science, technology, engineering, and mathematics in helping students develop critical thinking, problem-solving skills, and the ability to apply knowledge in real-world contexts. Interdisciplinary approaches within STEM have proven effective in enhancing student engagement and motivation. This paper presents supplementary materials designed to accompany worksheets containing interdisciplinary activities connecting mathematics and chemistry at the lower secondary school level. In these, students engage in solving chemistry-related tasks while highlighting links between the two disciplines through targeted hands-on learning. The supplementary materials include suggestions for widely known school experiments directly aligned with the topics of the worksheets. The first one, focused on chemical equations, features tasks related to the reaction of carbon with oxygen or an unknown oxide. The first reaction is supplemented by the experiment “Why Does the Candle Go Out?”, which requires basic laboratory equipment and limewater to demonstrate reaction conditions. This experiment also offers an opportunity to discuss the risks of carbon monoxide exposure, its properties, and first aid procedures. First aid and safe handling of chemicals comprise one of the core topics in chemistry education. The second worksheet, which explores the physical and chemical properties of a sugar cube, is enhanced by the experiment “Burning Sugar Cube”. Other tasks focus, for example, on reaction centres or natural pH indicators. Finally, students learn about more complex topics such as additive quantities or volume contraction. The chosen activities focus on everyday topics; the teacher feedback then highlights the potential of these supplementary experiments to enrich interdisciplinary teaching by fostering student motivation and eliciting deeper understanding of chemistry concepts.

Keywords: STEM education, interdisciplinary learning, chemistry experiments, mathematics integration, student motivation.