Mental arithmetic training application.
If you win 10 games in a row, you will go to the next level.
level1 : 200-30, 1000-80, ...
level2 : 700-140, 900-470, ...
level3 : 550-7, 470-9, ...
level4 : 900-2, 100-8, ...
level5 : 347-6, 779-8, ...
level6 : 881-2, 483-6, ...
level7 : 598-25, 456-44, ...
level8 : 935-52, 245-73, ...
level9 : 496-48, 583-27, ...
level10 : 923-47, 643-76, ...
In Japan, 8-9 years old (3rd grade)