ByeolDoSa: Arithmetic master

Key Features
1. Levels from basic to advanced
This app generates several arithmetic questions in different levels, from basic to advanced. 
The number of digits are adjusted in each levels and you can choose the level that needs to be practiced.
2. Column method mode
The column method mode let you calculate large numbers in easy way without the need of a pencil and paper.
You can do the training even in out of desk, in any place.
3. Summary of test records
Your repeated test record in persistent memory can show your improvement visually into graph presentation. 
For example you can see you are getting faster and faster on the calculation and getting good grade.