Mathematics outside the classroom – this work examines the characteristics of outdoor mathematics in more detail. Leaving the classroom to discover mathematics in the environment has several potential benefits for mathematics, e.g. the acquisition of skills and competencies. By means of an empirical study with secondary school students, the competencies of modelling, argumentation and problem-solving are taken into consideration. Therefore, the work outdoors at real objects is compared to the work inside the classroom. Similarities and differences are reported from three different perspectives: an observation perspective, the students’ perceptions perspective and a digital enrichment perspective. The results contribute to the question of what characterizes the work outdoors at real objects.