The popularity of artificial intelligence (AI) has highlighted the necessity of K-12 AI education, particularly at the elementary level. However, the lack of a comprehensive and age-appropriate AI curriculum integrated into school subjects, along with the abstract and complex nature of AI concepts, exacerbates student inequalities. Researchers addressed this by developing an AI curriculum using tangible computing tools and assessed its effectiveness in improving students' AI knowledge, perception, and behavioral intention. The study involved 60 elementary students from the US Midwest. The effectiveness of the curriculum and the students' learning experiences were investigated. The results demonstrated the success of the curriculum among all students, with improved AI knowledge, perception, and behavioral intention after using tangible computing tools. Four themes about learning experiences were identified: (1) Augmentation of cognitive learning gains, (2) Augmentation of affective attributes, (3) Advantages of utilizing tangible computing tools for AI education, and (4) Obstacles encountered in the process of learning AI. The practical and theoretical contributions and implications of this study are discussed.