It is a game to improve your memory, how quickly you can memorize the numbers.
There are "Level 1", "Level 2", and "Level 3" level buttons, and the higher the value, the shorter the time that the value is displayed.
When you press the level button, the number of digits button is displayed next, and there are "3 digits", "6 digits", and "9 digits". If you select the number of digits according to your level, the number of digits you selected immediately will be displayed. Since it is displayed in the square, memorize the numerical value and enter the numerical value in the "correct answer numerical input" field at the bottom. If the displayed numerical value and the memorized and entered numerical value match, the answer is "correct", and if they do not match, the answer is "incorrect". If the answer is incorrect, the part where the numerical value displayed on the square does not match is displayed in red. When finished, the level button will be displayed again, so take the next challenge.