Purpose: The paper aims to investigate how a tablet's design features, namely, its navigation design and visual appearance, influence users' enjoyment, concentration and control, when using tablets for problem-solving, and thereafter how their core flow experiences impact their perceived performance and efficiency with problem-solving. Design/methodology/approach: This study uses a field survey approach to engage 87 participants in a decision sciences class to use eTextbooks and a few other associated educational apps including CourseSmart app for e-notes and highlighting, sketchbook app and a calculator app in tablets to resolve class problems at a large US university. Findings: This study finds that the tablet's interface design features (navigation and visual appearance) make users engrossed in their problem-solving processes with perceived enjoyment, concentration and control. This, in turn, impacts their perceived performance and efficiency. Moreover, visual appearance plays the most significant role in arousing users' affective emotions (i.e. enjoyment), while interface navigation is crucial to engage users' deep concentration (i.e. cognition) and control for problem-solving. Practical implications: Modern tablets are being used widely in various sectors. More in-depth user flow experience design associated with tablet use for problem-solving contexts should be further advocated in order to provide more engaging and meaningful flow experiences to users. Originality/value: This study shows that the design of the tablet interface can engage users in problem-solving processes in both affective and cognitive ways. It provides valuable insights on tablet interface design for problem-solving.