Free Add Sub Mul Div Google Play

The app is intended for learning and improving long addition, subtraction, multiplication and division. The app has a practice mode, where the user can get help on how to solve the problem, and a test mode, where the user can test his/her skills.
The solution can be displayed step by step.
Some examples of problems that the app will give the user are:
1776 + 2017
987 - 152
234 * 12
180 / 15