Studies have highlighted the possible advantages of tangible user interfaces (TUIs) over multitouch interfaces (MTIs) in preschool education; however, more objective evidence is required to establish the superiority of TUIs. In this article, we design a mathematical application called THE NUMBERS to compare preschool children's learning potential and employed the eye-tracking method to assess the cognitive differences between the TUI and MTI versions. The results demonstrate that the TUI version participants made more attempts in the task, which was a significant predictor of learning outcomes. Furthermore, using TUIs leads to lower cognitive load, increases attention on key areas, and provides higher entertainment value, which has long-term effects on promoting preschool children's learning. The results of the perception questionnaire show that the TUI version is easier to use, more interesting, and more motivating for them to learn mathematics than the MTI version is. On the other hand, the interview results show that 62.5% of students prefer to use the TUI version to learn mathematics. The results can provide educators with a deeper understanding of the mental characteristics involved in MTIs and TUIs to enable them to design educational applications that are more suitable for preschool children.