Memory Math Game 100

In the game, you are asked to solve 100 math questions of from 10 levels (level 1 ~ level 10)
Starting from level 1 which is very easy (ex. 5 + 8 =? ), and higher the level, more difficult the quiz will be, but still the highest level 10 is not so much difficult apparently.
However, since the time limit for each question is only 10 seconds, achieving higher level is not so easy as it looks.

The game user inteferface is very simple and intuitive, so I hope you can play without any stress.

Can you really solve all 100 questions?