This article questions the design of mobile learning activities that lead students to spend time focusing on the mobile devices at the expense of interacting with other students or exploring the environment. This problem is approached from an interaction design perspective, designing and analysing geometry-learning activities. The authors present six guidelines for designing mobile learning activities, where mobile devices support rather than distract students from contents and contexts relevant to the learning goals. The guidelines are developed through video analysis of groups of middle school students doing learning activities outdoors and evaluated using the task model. The guidelines suggest that students (1) assume roles based on a different functionality of each device, (2) use devices as contextual tools, that the activities, (3) include physical interaction with the environment, (4) let teachers assume roles, (5) encourage face-to-face communication, and (6) introduce students to the mobile devices.