The purpose of this study was to contribute to the research on mathematics app use by very young children, and specifically mathematics apps for touch-screen mobile devices that contain virtual manipulatives. The study used a convergent parallel mixed methods design, in which quantitative and qualitative data were collected in parallel, analyzed separately, and then merged. During the study, 35 children, ages 3-4, interacted with four touch-screen mathematics apps on iPad devices during one-on one clinical interviews while learning seriation and counting. Researchers administered pre and post assessments of learning during the interviews. Each interview was videotaped using a wall-mounted camera and a GoPro camera to provide different views of the interview. Videos were analyzed to examine children's learning progressions, access of affordances, and patterns of behavior while interacting with the mathematics apps. The results suggest that different affordances of the individual apps were perceived in different ways, depending on the age of the child, and that these perceptions were observable in young children's patterns of behavior. Implications are discussed for iPad app use in young children's educational settings.