Your math exercise book
Now you can practice on iPhone.
Practice is the best way to know one thing.
1. You can setup practice level, includes type of operation, integer digits, and decimal places.
2. ALL practices record.
3. Save ALL record, if you login Facebook.
4. Collect rainbow everyday.
5. Share your rainbow to Facebook with your friends.
6. Recall your practice records, if you change device or reinstall the app.