Motivation and math anxiety are crucial in performance and satisfaction, and augmented reality (AR) may be a useful tool in enhancing these factors because it provides users with interesting visual experiences. Since related empirical research is limited in investigating the effects of using free mobile AR apps integrating Keller's ARCS (attention-relevance-confidence-satisfaction) motivation model on learning motivation, anxiety, and outcomes between students with different levels of anxiety in primary math education, this study investigated whether mobile AR differently affected learning, motivation, and math anxiety between students with high and low anxiety. The results showed that the AR group performed better than the non-AR group, and high-anxiety learners in the AR group outperformed in algebra and geometry. The AR group had higher motivation based on Keller's ARCS model. The high-anxiety learners had higher confidence and satisfaction and lower anxiety when learning using mobile AR. The AR users were satisfied with ease of use, usefulness, playfulness, and benefit from exploration and hands-on experiences. Moreover, high-anxiety users in the AR group had higher perceptions of exploration, hands-on experiences, and playfulness. This study includes the participants' experience in adopting mobile AR for their learning and discusses its constraints.