The app includes a mathematical learning game that was developed specifically for use in 7th grade mathematics lessons. In the game, players control a fictional character named X-Bert through a world full of numbers. The aim of the game is to help X-Bert find the ultimate snack. In the well-known Pac-Man manner, the players collect the numbers scattered in a total of 42 different labyrinths. These are added or subtracted to give a total, depending on whether X-Bert is on a green or red square. The aim is to reach a given term value by skilfully collecting the numbers. The players solve mathematical problem situations in a playful way and can intuitively discover, practice and reflect on the laws of calculation and properties of rational numbers. Above all, the game promotes foresighted thinking, well-founded decision-making and mental arithmetic. Players have to recognize which numbers will help them and which paths they have to take to achieve the goal. With special objects and fields, such as portals, moving walkways and switches, the game offers a high degree of variety and a wide range of versatile problem situations. The ability to restart each level at any time encourages exploration and experimentation in the game.
In the game, the players have to collect over 80 stars and unlock 20 characters. At the same time, strong learners find a challenge and weaker players an interesting approach to the topic of rational numbers.