In this game, the child must help Serge reach a hidden treasure on an island, in several repetitive steps.

For each step, he must find the missing number (complement) to reach the target number, using the + and minus buttons.
Each correct answer on the first attempt earns 1/2 star.

Didactic variables:
From the settings menu, the adult can modify the interval of numbers used as well as the maximum deviation.
Other options are also available:
- change the representation of numbers: digits, fingers, dominoes, dice
- display or not a graduated line to help with counting
- display or not a digital band
- lock options