Mental arithmetic training application.
If you win 10 games in a row, you will go to the next level.
level1 : 100-8, 100-6, ...
level2 : 100-20, 100-40, ...
level3 : 100-57, 100-32, ...
level4 : 107-4, 109-5, ...
level5 : 105-8, 101-7, ...
level6 : 106-80, 107-40, ...
level7 : 109-51, 104-62, ...
level8 : 104-36, 105-67, ...
level9 : 119-2, 116-5, ...
level10 : 112-8, 111-4, ...
In Japan, 7-8 years old (2nd grade)