This paper presents the first findings from Math Elements user experience (UX) studies. Math Elements is a game that makes the whole Finnish maths K-2 curriculum (kindergarten and primary school grades 1 and 2) available for players all over the world. The game is based on teachable agent approach, which means that in the game players can teach math skills to their game characters. Research focused on evaluating the implementation of the game, exploring players' opinions about the game, and studying how the game fits to classroom usage. The participants were Finnish (N = 111) and Irish (N = 42) primary school pupils. In both cases interviews, game log data and observation methods were used to evaluate the UX. The Finnish study was conducted in two phases. First, one first grade class (N = 23) participated in a focus group study in which they played the Math Elements game in small groups and finally eight of the pupils participated in an eye tracking study. Second, the class introduced the game in their school and after that all first and second graders of the school played the game daily during a three weeks period. The Irish case study was different from Finnish study and the results are not directly comparable. The Irish pupils (fourth and fifth graders) played the game for 50 minutes as a part of their regular schoolwork. In general, Math Elements was experienced as an engaging learning game in all studied age groups and it was found to fit well into classroom usage in certain contexts. The paper presents the details of the conducted UX studies and discusses the meaning of UX in educational games.