calYc uses the four basic arithmetic operations and defined number ranges to set arithmetic problems. The level of difficulty is determined by selectable symbols (hatching chick, standing chick, etc.).

If a selected symbol is chosen again, further application-related information (e.g., number ranges) and settings (e.g., time, sounds, multiplication tables) become available. If the time measurement is set, a maximum of 20 seconds is added for solutions at the most difficult level and a maximum of 10 seconds for solutions at other levels.